message: Use _ref to fix unhashable tensor error for eq change
diff: @@ -539,7 +539,8 @@ class AdamOptimizerTest(test.TestCase):
  opt = adam.Adam(1.)
  opt.minimize(lambda: v1 + v2, var_list=[v1, v2])
  # There should be iteration, and two unique slot variables for v1 and v2.
  - self.assertEqual(5, len(set(opt.variables())))
  + self.assertEqual(
  + 5, len(set([v.experimental_ref() for v in opt.variables()])))
  self.assertEqual(
  self.evaluate(opt.variables()[0]), self.evaluate(opt.iterations))
  