def testNoOtherGradients(self):
    """Tests no gradient propagates through things other than q_tm1."""
    static_args, _, retrace = self._get_retrace_core()
    gradients = tf.gradients([retrace.loss], static_args)
    self.assertEqual(gradients, [None] * len(gradients))
Tests no gradient propagates through things other than q_tm1.
trfl/retrace_ops_test.py