code: def spherical_yn(n, z, derivative=False):
      """Spherical Bessel function of the second kind or its derivative.
  
      Parameters
      ----------
      n : cupy.ndarray
          Order of the Bessel function.
      z : cupy.ndarray
          Argument of the Bessel function.
          Real-valued input.
      derivative : bool, optional
          If True, the value of the derivative (rather than the function
          itself) is returned.
  
      Returns
      -------
      yn : cupy.ndarray
  
      See Also
      -------
      :func:`scipy.special.spherical_yn`
  
      """
      if cupy.iscomplexobj(z):
          if derivative:
              raise NotImplementedError
          else:
              raise NotImplementedError
      else:
          if derivative:
              return _spherical_dyn_real(n, z)
          else:
              return _spherical_yn_real(n, z)
  
label_desc: Use image node_id 1 for calling a global function with example usage: spherical_yn(n, z, derivative) and returns: _spherical_dyn_real, _spherical_yn_real