docstr: Test that to_np returns correct observations.
code: def test_trajectory_to_np_observations(self):
      """Test that to_np returns correct observations."""
      tr = rl_task.Trajectory(observation=0)
      for obs in range(1, 3):
          self._extend(tr, new_observation=obs)
      tr_np = tr.to_np()
      np.testing.assert_array_equal(tr_np.observation, [0, 1, 2])
  
imports: import os
  from absl.testing import absltest
  import gym
  import numpy
  from trax import test_utils
  from trax.rl import task
label_desc: Use image node_id 11 for calling the TaskTest obj's underlying member method code with example usage: obj.test_trajectory_to_np_observations() without return types