public function getResponseHeader($key = null) {
        if (null != $key) {
            if (array_key_exists($key, $this->response_headers)) {
                return $this->response_headers[$key];
            }
        } else {
            return $this->response_headers;
        }
    }
public function getResponseHeader($key = null) {
        if (null != $key) {
            if (array_key_exists($key, $this->response_headers)) {
                return $this->response_headers[$key];
            }
        } else {
            return $this->response_headers;
        }
    }
public function getResponseHeader ( $ key = null ) { if ( null != $ key ) { if ( array_key_exists ( $ key , $ this -> response_headers ) ) { return $ this -> response_headers [ $ key ] ; } } else { return $ this -> response_headers ; } }
Get Response Header
@return type
Get Response Header