public function print_extra_script( $handle, $display = true ) {
    $output = $this->get_data( $handle, 'data' );
    if ( ! $output ) {
      return;
    }

    if ( ! $display ) {
      return $output;
    }

    wp_print_inline_script_tag( $output, array( 'id' => "{$handle}-js-extra" ) );

    return true;
  }