public function request_filesystem_credentials( $error = false, $context = '', $allow_relaxed_file_ownership = false ) {
    $url = $this->options['url'];
    if ( ! $context ) {
      $context = $this->options['context'];
    }
    if ( ! empty( $this->options['nonce'] ) ) {
      $url = wp_nonce_url( $url, $this->options['nonce'] );
    }

    $extra_fields = array();

    return request_filesystem_credentials( $url, '', $error, $context, $extra_fields, $allow_relaxed_file_ownership );
  }