<?php
/**
 * ObjectSerializer
 *
 * PHP version 7.4
 *
 * @category Class
 * @package  OpenAPI\Client
 * @author   OpenAPI Generator team
 * @link     https://openapi-generator.tech
 */

/**
 * Block Storage API
 *
 * Scaleway Block Storage provides network-attached storage that can be plugged in and out of cloud products such as Instances like a virtual hard-drive. Block Storage devices are independent from the local storage of Instances, and the fact that they are accessed over a network connection makes it easy to move them between Instances in the same Availability Zone.  (switchcolumn) <Message type=\"important\"> This page includes the API reference documentation for all Block Storage Low Latency offers. If you wish to use the Basic Block Storage offers, refer to the [Instances API documentation page](/api/instance/#path-volume-types-list-volume-types). </Message> (switchcolumn)  ## Quickstart  1. Configure your environment variables.     <Message type=\"note\">    This is an optional step that seeks to simplify your usage of the Block Storage API. See [Availability Zones](#availability-zones) below for help choosing an Availability Zone. You can find your Project ID in the [Scaleway console](https://console.scaleway.com/project/settings).    </Message>     ```bash    export SCW_SECRET_KEY=\"<API secret key>\"    export SCW_DEFAULT_ZONE=\"<Scaleway Availability Zone>\"    export SCW_PROJECT_ID=\"<Scaleway Project ID>\"    ```     <Message type=\"important\">    Make sure that the Availability Zone (AZ) is the same as the one of your Instance. Block volumes can only be attached to Instances in the same AZ.    </Message>  2. Edit the POST request payload you will use to create your Block volume. Replace the parameters in the following example:     ```json      '{      \"project_id\": \"d8e65f2b-cce9-40b7-80fc-6a2902db6826\",      \"name\": \"my-volume\",      \"perf_iops\": \"5000\",      \"tags\": [\"donnerstag\"],      \"from_empty\": {         \"size\": \"30000000000\"}      }'    ```     | Parameter    | Description                                                                                                                                                                                                                                                                                                                                                                          |    | :----------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |    | `project_id` | **REQUIRED** The ID of the Project you want to create your Block volume in. To find your Project ID you can **[list the projects](/api/account#path-projects-list-all-projects-of-an-organization)** or consult the **[Scaleway console](https://console.scaleway.com/project/settings)**.                                                                                           |    | `name`       | **REQUIRED** Name of the volume                                                                                                                                                                                                                                                                                                                                                      |    | `perf_iops`  | **REQUIRED** The maximum IO/s expected. This amount is a shared limit between write and read operations, it will be determined by your usage. You must specify either `5000`, or `15000`.                                                                                                                                                                                                                                     |    | `tags`       | The list of tags `[\"tag1\", \"tag2\", ...]` that will be associated with the Database Instance. Tags can be appended to the query of the [List Database Instances](#path-database-instances-list-database-instances) call to show results for only the Database Instances using a specific tag. You can also combine tags to list Database Instances that posess all the appended tags. |    | `from_empty` | When you create a brand new volume, as opposed to creating a volume from a snapshot, you must specifiy its size.                                                                                                                                                                                                                                                                     |    | `size`       | Volume size. The value should be expressed in bytes. For example 30GB is expressed as 30000000000                                                                                                                                                                                                                                                                                    |  3. Create a Block volume by running the following command. Make sure you include the payload you edited in the previous step.     ```bash    curl -X POST \\      -H \"X-Auth-Token: $SCW_SECRET_KEY\" \\      \"Content-Type: application/json\" \\      https://api.scaleway.com/block/v1alpha1/zone/$SCW_DEFAULT_ZONE/volumes \\      -d '{           \"project_id\": \"'\"$SCW_PROJECT_ID\"'\",           \"name\": \"my-volume\",           \"perf_iops\": \"5000\",           \"tags\": [\"donnerstag\"],           \"from_empty\": {               \"size\": \"30000000000\"}         }'    ```     An output similar to the following displays :     ```json    '{       \"id\": \"e337a374-f19a-4b58-a45d-75076f75fbc5\",       \"name\": \"my-volume\",       \"type\": \"sbs_5k\",       \"size\": 30000000000,       \"project_id\": \"d8e65f2b-cce9-40b7-80fc-6a2902db6826\",       \"created_at\": \"2023-09-28T15:48:59.105240Z\",       \"updated_at\": \"2023-09-28T15:48:59.105240Z\",       \"references\": [],       \"parent_snapshot_id\": None,       \"status\": \"creating\",       \"tags\": [],       \"specs\": {\"perf_iops\": 5000, \"class\": \"sbs\"},       \"zone\": \"fr-par-1\"       }'    ```      <Message type=\"note\">       Make sure to save the `id` of your volume, as it will be required in the next step.     </Message>  4. Attach your volume to your Instance using the Instance API [Update an Instance](/api/instance/#path-instances-update-an-instance) call.      <Message type=\"note\">       Make sure the Block volume is created and ready before attaching it to the Instance.     </Message>      <Message type=\"important\">       Make sure you include all your Instance's existing volumes in the payload, as the update can only be done to all or none of the volumes.        The payload should include a minimum of one key (`\"0\"`) with a value equivalent to the setting parameters for the volume.       Additional keys for additional volumes should increment by 1 each time. For example, the second volume is `\"1\"`, the third `\"2\"`, and so on.     </Message>     ```bash    curl -X PATCH \\      -H \"X-Auth-Token: $SCW_SECRET_KEY\" \\      \"Content-Type: application/json\" \\      https://api.scaleway.com/instance/v1/zone/$SCW_DEFAULT_ZONE/servers/$INSTANCE_ID \\      -d '{          \"volumes\": {             \"0\": {                \"boot\": false,                \"id\": \"571c8a17-ba68-4c1d-b137-bbd5bc7af104\",                \"volume_type\": \"System volume\"             }             \"1\": {                \"boot\": false,                \"id\": \"e337a374-f19a-4b58-a45d-75076f75fbc5\",                \"volume_type\": \"sbs_volume\"             }          }'    ```  Your Block volume is ready to be used with your Instance.  Refer to the [How to mount and use your Block volume](https://www.scaleway.com/en/docs/storage/block/how-to/mount-and-use-volume/) documentation page to do so.  (switchcolumn) <Message type=\"requirement\"> To perform the following steps, you must first ensure that:  - you have an account and are logged into the [Scaleway console](https://console.scaleway.com/organization) - you have created an [API key](https://www.scaleway.com/en/docs/identity-and-access-management/iam/how-to/create-api-keys/) and that the API key has sufficient [IAM permissions](https://www.scaleway.com/en/docs/identity-and-access-management/iam/reference-content/permission-sets/) to perform the actions described on this page. - you have [installed `curl`](https://curl.se/download.html) - you have [created an Instance](/instance/#path-instances-create-an-instance). </Message> (switchcolumn)  ## Going further  For further information and assitance for Scaleway Block Storage, check out the following resources:  - [Basic Block Storage Documentation](https://www.scaleway.com/en/docs/storage/block/) - [#block channel in the Scaleway Slack Community](scaleway-community.slack.com) - [How to open a support ticket](https://www.scaleway.com/en/docs/console/my-account/how-to/open-a-support-ticket/).
 *
 * The version of the OpenAPI document: v1alpha1
 * Generated by: https://openapi-generator.tech
 * Generator version: 7.11.0
 */

/**
 * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
 * https://openapi-generator.tech
 * Do not edit the class manually.
 */

namespace OpenAPI\Client;

use GuzzleHttp\Psr7\Utils;
use OpenAPI\Client\Model\ModelInterface;

/**
 * ObjectSerializer Class Doc Comment
 *
 * @category Class
 * @package  OpenAPI\Client
 * @author   OpenAPI Generator team
 * @link     https://openapi-generator.tech
 */
class ObjectSerializer
{
    /** @var string */
    private static $dateTimeFormat = \DateTime::ATOM;

    /**
     * Change the date format
     *
     * @param string $format   the new date format to use
     */
    public static function setDateTimeFormat($format)
    {
        self::$dateTimeFormat = $format;
    }

    /**
     * Serialize data
     *
     * @param mixed  $data   the data to serialize
     * @param string|null $type   the OpenAPIToolsType of the data
     * @param string|null $format the format of the OpenAPITools type of the data
     *
     * @return scalar|object|array|null serialized form of $data
     */
    public static function sanitizeForSerialization($data, $type = null, $format = null)
    {
        if (is_scalar($data) || null === $data) {
            return $data;
        }

        if ($data instanceof \DateTime) {
            return ($format === 'date') ? $data->format('Y-m-d') : $data->format(self::$dateTimeFormat);
        }

        if (is_array($data)) {
            foreach ($data as $property => $value) {
                $data[$property] = self::sanitizeForSerialization($value);
            }
            return $data;
        }

        if (is_object($data)) {
            $values = [];
            if ($data instanceof ModelInterface) {
                $formats = $data::openAPIFormats();
                foreach ($data::openAPITypes() as $property => $openAPIType) {
                    $getter = $data::getters()[$property];
                    $value = $data->$getter();
                    if ($value !== null && !in_array($openAPIType, ['\DateTime', '\SplFileObject', 'array', 'bool', 'boolean', 'byte', 'float', 'int', 'integer', 'mixed', 'number', 'object', 'string', 'void'], true)) {
                        $callable = [$openAPIType, 'getAllowableEnumValues'];
                        if (is_callable($callable)) {
                            /** array $callable */
                            $allowedEnumTypes = $callable();
                            if (!in_array($value, $allowedEnumTypes, true)) {
                                $imploded = implode("', '", $allowedEnumTypes);
                                throw new \InvalidArgumentException("Invalid value for enum '$openAPIType', must be one of: '$imploded'");
                            }
                        }
                    }
                    if (($data::isNullable($property) && $data->isNullableSetToNull($property)) || $value !== null) {
                        $values[$data::attributeMap()[$property]] = self::sanitizeForSerialization($value, $openAPIType, $formats[$property]);
                    }
                }
            } else {
                foreach($data as $property => $value) {
                    $values[$property] = self::sanitizeForSerialization($value);
                }
            }
            return (object)$values;
        } else {
            return (string)$data;
        }
    }

    /**
     * Sanitize filename by removing path.
     * e.g. ../../sun.gif becomes sun.gif
     *
     * @param string $filename filename to be sanitized
     *
     * @return string the sanitized filename
     */
    public static function sanitizeFilename($filename)
    {
        if (preg_match("/.*[\/\\\\](.*)$/", $filename, $match)) {
            return $match[1];
        } else {
            return $filename;
        }
    }

    /**
     * Shorter timestamp microseconds to 6 digits length.
     *
     * @param string $timestamp Original timestamp
     *
     * @return string the shorten timestamp
     */
    public static function sanitizeTimestamp($timestamp)
    {
        if (!is_string($timestamp)) return $timestamp;

        return preg_replace('/(:\d{2}.\d{6})\d*/', '$1', $timestamp);
    }

    /**
     * Take value and turn it into a string suitable for inclusion in
     * the path, by url-encoding.
     *
     * @param string $value a string which will be part of the path
     *
     * @return string the serialized object
     */
    public static function toPathValue($value)
    {
        return rawurlencode(self::toString($value));
    }

    /**
     * Checks if a value is empty, based on its OpenAPI type.
     *
     * @param mixed  $value
     * @param string $openApiType
     *
     * @return bool true if $value is empty
     */
    private static function isEmptyValue($value, string $openApiType): bool
    {
        # If empty() returns false, it is not empty regardless of its type.
        if (!empty($value)) {
            return false;
        }

        # Null is always empty, as we cannot send a real "null" value in a query parameter.
        if ($value === null) {
            return true;
        }

        switch ($openApiType) {
            # For numeric values, false and '' are considered empty.
            # This comparison is safe for floating point values, since the previous call to empty() will
            # filter out values that don't match 0.
            case 'int':
            case 'integer':
                return $value !== 0;

            case 'number':
            case 'float':
                return $value !== 0 && $value !== 0.0;

            # For boolean values, '' is considered empty
            case 'bool':
            case 'boolean':
                return !in_array($value, [false, 0], true);

            # For string values, '' is considered empty.
            case 'string':
                return $value === '';

            # For all the other types, any value at this point can be considered empty.
            default:
                return true;
        }
    }

    /**
     * Take query parameter properties and turn it into an array suitable for
     * native http_build_query or GuzzleHttp\Psr7\Query::build.
     *
     * @param mixed  $value       Parameter value
     * @param string $paramName   Parameter name
     * @param string $openApiType OpenAPIType eg. array or object
     * @param string $style       Parameter serialization style
     * @param bool   $explode     Parameter explode option
     * @param bool   $required    Whether query param is required or not
     *
     * @return array
     */
    public static function toQueryValue(
        $value,
        string $paramName,
        string $openApiType = 'string',
        string $style = 'form',
        bool $explode = true,
        bool $required = true
    ): array {

        # Check if we should omit this parameter from the query. This should only happen when:
        #  - Parameter is NOT required; AND
        #  - its value is set to a value that is equivalent to "empty", depending on its OpenAPI type. For
        #    example, 0 as "int" or "boolean" is NOT an empty value.
        if (self::isEmptyValue($value, $openApiType)) {
            if ($required) {
                return ["{$paramName}" => ''];
            } else {
                return [];
            }
        }

        # Handle DateTime objects in query
        if($openApiType === "\\DateTime" && $value instanceof \DateTime) {
            return ["{$paramName}" => $value->format(self::$dateTimeFormat)];
        }

        $query = [];
        $value = (in_array($openApiType, ['object', 'array'], true)) ? (array)$value : $value;

        // since \GuzzleHttp\Psr7\Query::build fails with nested arrays
        // need to flatten array first
        $flattenArray = function ($arr, $name, &$result = []) use (&$flattenArray, $style, $explode) {
            if (!is_array($arr)) return $arr;

            foreach ($arr as $k => $v) {
                $prop = ($style === 'deepObject') ? $prop = "{$name}[{$k}]" : $k;

                if (is_array($v)) {
                    $flattenArray($v, $prop, $result);
                } else {
                    if ($style !== 'deepObject' && !$explode) {
                        // push key itself
                        $result[] = $prop;
                    }
                    $result[$prop] = $v;
                }
            }
            return $result;
        };

        $value = $flattenArray($value, $paramName);

        // https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#style-values
        if ($openApiType === 'array' && $style === 'deepObject' && $explode) {
            return $value;
        }

        if ($openApiType === 'object' && ($style === 'deepObject' || $explode)) {
            return $value;
        }

        if ('boolean' === $openApiType && is_bool($value)) {
            $value = self::convertBoolToQueryStringFormat($value);
        }

        // handle style in serializeCollection
        $query[$paramName] = ($explode) ? $value : self::serializeCollection((array)$value, $style);

        return $query;
    }

    /**
     * Convert boolean value to format for query string.
     *
     * @param bool $value Boolean value
     *
     * @return int|string Boolean value in format
     */
    public static function convertBoolToQueryStringFormat(bool $value)
    {
        if (Configuration::BOOLEAN_FORMAT_STRING == Configuration::getDefaultConfiguration()->getBooleanFormatForQueryString()) {
            return $value ? 'true' : 'false';
        }

        return (int) $value;
    }

    /**
     * Take value and turn it into a string suitable for inclusion in
     * the header. If it's a string, pass through unchanged
     * If it's a datetime object, format it in ISO8601
     *
     * @param string $value a string which will be part of the header
     *
     * @return string the header string
     */
    public static function toHeaderValue($value)
    {
        $callable = [$value, 'toHeaderValue'];
        if (is_callable($callable)) {
            return $callable();
        }

        return self::toString($value);
    }

    /**
     * Take value and turn it into a string suitable for inclusion in
     * the http body (form parameter). If it's a string, pass through unchanged
     * If it's a datetime object, format it in ISO8601
     *
     * @param string|\SplFileObject $value the value of the form parameter
     *
     * @return string the form string
     */
    public static function toFormValue($value)
    {
        if ($value instanceof \SplFileObject) {
            return $value->getRealPath();
        } else {
            return self::toString($value);
        }
    }

    /**
     * Take value and turn it into a string suitable for inclusion in
     * the parameter. If it's a string, pass through unchanged
     * If it's a datetime object, format it in ISO8601
     * If it's a boolean, convert it to "true" or "false".
     *
     * @param float|int|bool|\DateTime $value the value of the parameter
     *
     * @return string the header string
     */
    public static function toString($value)
    {
        if ($value instanceof \DateTime) { // datetime in ISO8601 format
            return $value->format(self::$dateTimeFormat);
        } elseif (is_bool($value)) {
            return $value ? 'true' : 'false';
        } else {
            return (string) $value;
        }
    }

    /**
     * Serialize an array to a string.
     *
     * @param array  $collection                 collection to serialize to a string
     * @param string $style                      the format use for serialization (csv,
     * ssv, tsv, pipes, multi)
     * @param bool   $allowCollectionFormatMulti allow collection format to be a multidimensional array
     *
     * @return string
     */
    public static function serializeCollection(array $collection, $style, $allowCollectionFormatMulti = false)
    {
        if ($allowCollectionFormatMulti && ('multi' === $style)) {
            // http_build_query() almost does the job for us. We just
            // need to fix the result of multidimensional arrays.
            return preg_replace('/%5B[0-9]+%5D=/', '=', http_build_query($collection, '', '&'));
        }
        switch ($style) {
            case 'pipeDelimited':
            case 'pipes':
                return implode('|', $collection);

            case 'tsv':
                return implode("\t", $collection);

            case 'spaceDelimited':
            case 'ssv':
                return implode(' ', $collection);

            case 'simple':
            case 'csv':
                // Deliberate fall through. CSV is default format.
            default:
                return implode(',', $collection);
        }
    }

    /**
     * Deserialize a JSON string into an object
     *
     * @param mixed    $data          object or primitive to be deserialized
     * @param string   $class         class name is passed as a string
     * @param string[]|null $httpHeaders   HTTP headers
     *
     * @return object|array|null a single or an array of $class instances
     */
    public static function deserialize($data, $class, $httpHeaders = null)
    {
        if (null === $data) {
            return null;
        }

        if (strcasecmp(substr($class, -2), '[]') === 0) {
            $data = is_string($data) ? json_decode($data) : $data;

            if (!is_array($data)) {
                throw new \InvalidArgumentException("Invalid array '$class'");
            }

            $subClass = substr($class, 0, -2);
            $values = [];
            foreach ($data as $key => $value) {
                $values[] = self::deserialize($value, $subClass, null);
            }
            return $values;
        }

        if (preg_match('/^(array<|map\[)/', $class)) { // for associative array e.g. array<string,int>
            $data = is_string($data) ? json_decode($data) : $data;
            settype($data, 'array');
            $inner = substr($class, 4, -1);
            $deserialized = [];
            if (strrpos($inner, ",") !== false) {
                $subClass_array = explode(',', $inner, 2);
                $subClass = $subClass_array[1];
                foreach ($data as $key => $value) {
                    $deserialized[$key] = self::deserialize($value, $subClass, null);
                }
            }
            return $deserialized;
        }

        if ($class === 'object') {
            settype($data, 'array');
            return $data;
        } elseif ($class === 'mixed') {
            settype($data, gettype($data));
            return $data;
        }

        if ($class === '\DateTime') {
            // Some APIs return an invalid, empty string as a
            // date-time property. DateTime::__construct() will return
            // the current time for empty input which is probably not
            // what is meant. The invalid empty string is probably to
            // be interpreted as a missing field/value. Let's handle
            // this graceful.
            if (!empty($data)) {
                try {
                    return new \DateTime($data);
                } catch (\Exception $exception) {
                    // Some APIs return a date-time with too high nanosecond
                    // precision for php's DateTime to handle.
                    // With provided regexp 6 digits of microseconds saved
                    return new \DateTime(self::sanitizeTimestamp($data));
                }
            } else {
                return null;
            }
        }

        if ($class === '\SplFileObject') {
            $data = Utils::streamFor($data);

            /** @var \Psr\Http\Message\StreamInterface $data */

            // determine file name
            if (
                is_array($httpHeaders)
                && array_key_exists('Content-Disposition', $httpHeaders)
                && preg_match('/inline; filename=[\'"]?([^\'"\s]+)[\'"]?$/i', $httpHeaders['Content-Disposition'], $match)
            ) {
                $filename = Configuration::getDefaultConfiguration()->getTempFolderPath() . DIRECTORY_SEPARATOR . self::sanitizeFilename($match[1]);
            } else {
                $filename = tempnam(Configuration::getDefaultConfiguration()->getTempFolderPath(), '');
            }

            $file = fopen($filename, 'w');
            while ($chunk = $data->read(200)) {
                fwrite($file, $chunk);
            }
            fclose($file);

            return new \SplFileObject($filename, 'r');
        }

        /** @psalm-suppress ParadoxicalCondition */
        if (in_array($class, ['\DateTime', '\SplFileObject', 'array', 'bool', 'boolean', 'byte', 'float', 'int', 'integer', 'mixed', 'number', 'object', 'string', 'void'], true)) {
            settype($data, $class);
            return $data;
        }


        if (method_exists($class, 'getAllowableEnumValues')) {
            if (!in_array($data, $class::getAllowableEnumValues(), true)) {
                $imploded = implode("', '", $class::getAllowableEnumValues());
                throw new \InvalidArgumentException("Invalid value for enum '$class', must be one of: '$imploded'");
            }
            return $data;
        } else {
            $data = is_string($data) ? json_decode($data) : $data;

            if (is_array($data)) {
                $data = (object)$data;
            }

            // If a discriminator is defined and points to a valid subclass, use it.
            $discriminator = $class::DISCRIMINATOR;
            if (!empty($discriminator) && isset($data->{$discriminator}) && is_string($data->{$discriminator})) {
                $subclass = '\OpenAPI\Client\Model\\' . $data->{$discriminator};
                if (is_subclass_of($subclass, $class)) {
                    $class = $subclass;
                }
            }

            /** @var ModelInterface $instance */
            $instance = new $class();
            foreach ($instance::openAPITypes() as $property => $type) {
                $propertySetter = $instance::setters()[$property];

                if (!isset($propertySetter)) {
                    continue;
                }

                if (!isset($data->{$instance::attributeMap()[$property]})) {
                    if ($instance::isNullable($property)) {
                        $instance->$propertySetter(null);
                    }

                    continue;
                }

                if (isset($data->{$instance::attributeMap()[$property]})) {
                    $propertyValue = $data->{$instance::attributeMap()[$property]};
                    $instance->$propertySetter(self::deserialize($propertyValue, $type, null));
                }
            }
            return $instance;
        }
    }

    /**
    * Build a query string from an array of key value pairs.
    *
    * This function can use the return value of `parse()` to build a query
    * string. This function does not modify the provided keys when an array is
    * encountered (like `http_build_query()` would).
    *
    * The function is copied from https://github.com/guzzle/psr7/blob/a243f80a1ca7fe8ceed4deee17f12c1930efe662/src/Query.php#L59-L112
    * with a modification which is described in https://github.com/guzzle/psr7/pull/603
    *
    * @param array     $params              Query string parameters.
    * @param int|false $encoding            Set to false to not encode, PHP_QUERY_RFC3986
    *                                       to encode using RFC3986, or PHP_QUERY_RFC1738
    *                                       to encode using RFC1738.
    */
    public static function buildQuery(array $params, $encoding = PHP_QUERY_RFC3986): string
    {
        if (!$params) {
            return '';
        }

        if ($encoding === false) {
            $encoder = function (string $str): string {
                return $str;
            };
        } elseif ($encoding === PHP_QUERY_RFC3986) {
            $encoder = 'rawurlencode';
        } elseif ($encoding === PHP_QUERY_RFC1738) {
            $encoder = 'urlencode';
        } else {
            throw new \InvalidArgumentException('Invalid type');
        }

        $castBool = Configuration::BOOLEAN_FORMAT_INT == Configuration::getDefaultConfiguration()->getBooleanFormatForQueryString()
            ? function ($v) { return (int) $v; }
            : function ($v) { return $v ? 'true' : 'false'; };

        $qs = '';
        foreach ($params as $k => $v) {
            $k = $encoder((string) $k);
            if (!is_array($v)) {
                $qs .= $k;
                $v = is_bool($v) ? $castBool($v) : $v;
                if ($v !== null) {
                    $qs .= '='.$encoder((string) $v);
                }
                $qs .= '&';
            } else {
                foreach ($v as $vv) {
                    $qs .= $k;
                    $vv = is_bool($vv) ? $castBool($vv) : $vv;
                    if ($vv !== null) {
                        $qs .= '='.$encoder((string) $vv);
                    }
                    $qs .= '&';
                }
            }
        }

        return $qs ? (string) substr($qs, 0, -1) : '';
    }
}