docstr: Test that the specified number of interactions are collected.
code: def test_collects_specified_number_of_trajectories(self):
      """Test that the specified number of interactions are collected."""
      task = rl_task.RLTask(
          DummyEnv(), initial_trajectories=0, max_steps=3, time_limit=20
      )
      task.collect_trajectories(
          policy=(lambda _: (0, 0)), n_trajectories=3
      )
      trajectories = task.trajectories[
          1
      ]  # Get trajectories from epoch 1.
      self.assertLen(trajectories, 3)
  
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 18 for calling the TaskTest obj's underlying member method code with example usage: obj.test_collects_specified_number_of_trajectories() without return types