code: def test_get_agent_timestep(self):
      agent_indices = ["a", "99", "Z"]
      spec = multiagent_fakes.make_multiagent_environment_spec(
          agent_indices
      )
      env = fakes.Environment(spec)
      timestep = env.reset()
      for agent_id in spec.actions.keys():
          single_agent_timestep = multiagent_utils.get_agent_timestep(
              timestep, agent_id
          )
          expected_timestep = dm_env.TimeStep(
              observation=timestep.observation[agent_id],
              reward=None,
              discount=None,
              step_type=timestep.step_type,
          )
          self.assertEqual(single_agent_timestep, expected_timestep)
  
file_path: acme/acme/multiagent/utils_test.py
imports: from acme import specs
  from acme.multiagent import utils
  from acme.testing import fakes
  from acme.testing import multiagent_fakes
  import dm_env
  from absl.testing import absltest
label_desc: Use image node_id 2 for calling the UtilsTest obj's underlying member method code with example usage: obj.test_get_agent_timestep() without return types