code: def cost5(
      x, axis=None
  ):  # XXX: axis ignored, or better raise if not None?
      """a 5d test function, with axis keyword (ignored)
  
      For example:
        >>> cost5([1,2,3,4,5], axis=None)
        13.922847983320086
        >>> cost5([1,2,3,4,5], axis=0)
        13.922847983320086
      """
      y = function5(x)
      return y
  
label_desc: Use image node_id 6 for calling a global function with example usage: cost5(x, axis) and returns: y