def _fresh_grad(self):
        """Whether this array's corresponding gradient array
        (registered via `autograd.mark_variables`) has been
        updated by `autograd.backward` since last reset.

        `_fresh_grad` need to be manually set to False
        after consuming gradient (usually after updating this
        array).
        """
        out = ctypes.c_int()
        check_call(_LIB.MXNDArrayGetGradState(self.handle, ctypes.byref(out)))
        return out.value
Whether this array's corresponding gradient array
        (registered via `autograd.mark_variables`) has been
        updated by `autograd.backward` since last reset.

        `_fresh_grad` need to be manually set to False
        after consuming gradient (usually after updating this
        array).