code: def gradient(self, wrt):
          
          handle = SymbolHandle()
          c_wrt = c_str_array(wrt)
          check_call(_LIB.MXSymbolGrad(self.handle,
                                       mx_uint(len(wrt)),
                                       c_wrt,
                                       ctypes.byref(handle)))
          return Symbol(handle)
docs: Gets the autodiff of current symbol.
  
          This function can only be used if current symbol is a loss function.
  
          .. note:: This function is currently not implemented.
  
          Parameters
          ----------
          wrt : Array of String
              keyword arguments of the symbol that the gradients are taken.
  
          Returns
          -------
          grad : Symbol
              A gradient Symbol with returns to be the corresponding gradients.