code: def test_default_observation(self):
      observation = self._env._default_observation(
          self._env.observation_spec()[0], 0
      )
      self.assert_equal(
          observation, {"mock": np.zeros([10, 1], dtype=np.int32)}
      )
  
imports: from absl.testing import absltest
  import mock
  import numpy
  from pysc2.env import enums
  from pysc2.env import environment
  from pysc2.env import mock_sc2_env
  from pysc2.env import sc2_env
  from pysc2.lib import features
  from s2clientprotocol import common_pb2
  from s2clientprotocol import raw_pb2
  from s2clientprotocol import sc2api_pb2
label_desc: Use image node_id 4 for calling the TestTestEnvironment obj's underlying member method code with example usage: obj.test_default_observation() without return types