code: protected static function save_external_file( $url, $path ) {
  
  		$data = file_get_contents( $url );
  
  		return ( $data && self::save_file( $path, $data ) ) ? $data : '';
  	}
docs: Save external file.
  
  @since 1.0.4
  
  @param string $url  → external url.
  @param string $path → internal file path.
  
  @return string → file content or empty