def METHOD_NAME(self):
    a = jt.array([1.0,2.0,3.0])
    b = (jt.maximum(a, 0)).sum() * 2.0
    da = jt.grad(b, a)
    jt.sync_all()
    assert (a.data==[1,2,3]).all()
    assert (da.data==[2,2,2]).all()