message: add a backend test for product with numpy array as axis input
diff: @@ -578,6 +578,11 @@ class TestBackendOps(unittest.TestCase):
  def testProdAxis(self, b):
  return b.prod(b.variable(m(2, 3, 4, 5)), axis=[1, 3])
  + # TODO(T1026): Switch to opTest once PROD AggregationOp supports derivatives
  + @compareForwardClose()
  + def testProdAxisNumpy(self, b):
  + return b.prod(b.variable(m(2, 3, 4, 5)), axis=np.array((1, 3)))
  +
  # TODO(T1026): Switch to opTest once PROD AggregationOp supports derivs
  @compareForwardClose()
  def testProdNegAxis(self, b):
  