code: def time_symmetrize(clip):
      """
      Returns a clip that plays the current clip once forwards and
      then once backwards. This is very practival to make video that
      loop well, e.g. to create animated GIFs.
      This effect is automatically applied to the clip's mask and audio
      if they exist.
      """
      return clip + clip[::-1]
  
label_desc: Use image node_id 1 for calling a global function with example usage: time_symmetrize(clip) and returns: unknown