code: def fm_demod(x, axis=-1):
      """
      Demodulate Frequency Modulated Signal
  
      Parameters
      ----------
      x : ndarray
          Received complex valued signal or batch of signals
  
      Returns
      -------
      y : ndarray
          The demodulated output with the same shape as `x`.
      """
  
      x = cp.asarray(x)
  
      if cp.isrealobj(x):
          raise AssertionError("Input signal must be complex-valued")
      x_angle = cp.unwrap(cp.angle(x), axis=axis)
      y = cp.diff(x_angle, axis=axis)
      return y
  
label_desc: Use image node_id 1 for calling a global function with example usage: fm_demod(x, axis) and returns: y