code: def testStepTrainCustomObservationShapes(self):
      custom_shapes = [
          (1,),
          (4, 4),
          (6, 1),
          (1, 6),
          (1, 1, 6),
          (6, 6, 6, 6),
      ]
      for shape in custom_shapes:
          self._custom_shapes_test(shape, jnp.uint8, 1)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import shutil
  from absl import flags
  from absl.testing import absltest
  from dopamine.discrete_domains import atari_lib
  from dopamine.jax.agents.dqn import dqn_agent
  from dopamine.utils import test_utils
  from flax import linen
  import gin
  import jax.numpy
  import mock
  import numpy
label_desc: Use image node_id 10 for calling the DQNAgentTest obj's underlying member method code with example usage: obj.testStepTrainCustomObservationShapes() without return types