code: def testCreatePlaceholderWithNameScope(self):
      self.skipIfExecutingEagerly()
      obs_spec = tensor_spec.TensorSpec([2], tf.float32, "obs")
      time_step_spec = ts.time_step_spec(obs_spec)
      ph = tensor_spec.to_nest_placeholder(
          time_step_spec, name_scope="action"
      )
      self.assertEqual(ph.observation.name, "action/obs:0")
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tf_agents.specs import array_spec
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import time_step
label_desc: Use image node_id 4 for calling the ToPlaceholderTest obj's underlying member method code with example usage: obj.testCreatePlaceholderWithNameScope() without return types