public function setResponseType($responseType = 'array')
    {
        $supportedFormats = array('json', 'html', 'extjs', 'text', 'png');

        if (in_array($responseType, $supportedFormats)) {
            $this->fakeType = false;
            $this->responseType = $responseType;
        } else {
            switch ($responseType) {
                case 'pngb64':
                    $this->fakeType = 'pngb64';
                    $this->responseType = 'png';
                    break;
                case 'object':
                case 'array':
                    $this->responseType = 'json';
                    $this->fakeType = $responseType;
                    break;
                default:
                    $this->responseType = 'json';
                    $this->fakeType = 'array'; // Default format
            }
        }
    }