src/Client/QueryParam.php
public function buildQueryString($options)
    {
        $options = $this->resolve($options);

        foreach ($this->formParameters as $key => $isFormParameter) {
            if ($isFormParameter && isset($options[$key])) {
                unset($options[$key]);
            }
        }

        foreach ($this->headerParameters as $key => $isHeaderParameter) {
            if ($isHeaderParameter && isset($options[$key])) {
                unset($options[$key]);
            }
        }

        return http_build_query($options);
    }
public function buildQueryString($options)
    {
        $options = $this->resolve($options);

        foreach ($this->formParameters as $key => $isFormParameter) {
            if ($isFormParameter && isset($options[$key])) {
                unset($options[$key]);
            }
        }

        foreach ($this->headerParameters as $key => $isHeaderParameter) {
            if ($isHeaderParameter && isset($options[$key])) {
                unset($options[$key]);
            }
        }

        return http_build_query($options);
    }
Build the query string.

@param $options

@return string