code: def _get_obs(self):
      return self._builder.build().observation
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from pysc2.lib import actions
  from pysc2.lib import features
  from pysc2.lib import point
  from pysc2.lib import units
  from pysc2.tests import dummy_observation
  from s2clientprotocol import common_pb2
label_desc: Use image node_id 20 for calling the DummyObservationTest obj's underlying member method code with example usage: obj._get_obs() and returns: self