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.

def gradient(self, wrt):
        """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.
        """
        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)