public function send_headers() {
    if ( function_exists( 'gc_enable' ) ) {
      gc_enable(); // phpcs:ignore PHPCompatibility.FunctionUse.NewFunctions.gc_enableFound
    }
    if ( function_exists( 'apache_setenv' ) ) {
      @apache_setenv( 'no-gzip', 1 ); // @codingStandardsIgnoreLine
    }
    @ini_set( 'zlib.output_compression', 'Off' ); // @codingStandardsIgnoreLine
    @ini_set( 'output_buffering', 'Off' ); // @codingStandardsIgnoreLine
    @ini_set( 'output_handler', '' ); // @codingStandardsIgnoreLine
    ignore_user_abort( true );
    wc_set_time_limit( 0 );
    wc_nocache_headers();
    header( 'Content-Type: text/csv; charset=utf-8' );
    header( 'Content-Disposition: attachment; filename=' . $this->get_filename() );
    header( 'Pragma: no-cache' );
    header( 'Expires: 0' );
  }