azure-storage-common/src/Common/Internal/ServiceRestProxy.php
public function addPostParameter(
        array $postParameters,
        $key,
        $value
    ) {
        Validate::isArray($postParameters, 'postParameters');
        $postParameters[$key] = $value;
        return $postParameters;
    }
public function addPostParameter(
        array $postParameters,
        $key,
        $value
    ) {
        Validate::isArray($postParameters, 'postParameters');
        $postParameters[$key] = $value;
        return $postParameters;
    }
Adds HTTP POST parameter to the specified

@param array  $postParameters An array of HTTP POST parameters.
@param string $key            The key of a HTTP POST parameter.
@param string $value          the value of a HTTP POST parameter.

@return array