private static function to_theme_file_uri( array $src ) {
    $placeholder = 'file:./';

    foreach ( $src as $src_key => $src_url ) {
      // Skip if the src doesn't start with the placeholder, as there's nothing to replace.
      if ( ! str_starts_with( $src_url, $placeholder ) ) {
        continue;
      }

      $src_file        = str_replace( $placeholder, '', $src_url );
      $src[ $src_key ] = get_theme_file_uri( $src_file );
    }

    return $src;
  }