code: def testNoOtherGradients(self):
      # Gradients are only defined for logits_q_tm1, not any other input.
      # Bellman residual variants could potentially generate a gradient wrt q_t.
      gradients = tf.gradients(
          [self.qlearning.loss],
          [
              self.logits_q_t,
              self.r_t,
              self.a_tm1,
              self.pcont_t,
              self.atoms_t,
              self.atoms_tm1,
              self.q_t_selector,
          ],
      )
      self.assertEqual(gradients, [None for _ in gradients])
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import tensorflow.compat.v1
  from trfl import dist_value_ops
label_desc: Use image node_id 7 for calling the CategoricalDistDoubleQLearningTest obj's underlying member method code with example usage: obj.testNoOtherGradients() without return types