class_docstr: A trajectory of interactions with a RL environment.
  
  Trajectories are created when interacting with an RL environment. They can
  be prolonged and sliced and when completed, allow to re-calculate returns.
class_docstr_tok: ["A","trajectory","of","interactions","with","a","RL","environment",".","Trajectories","are","created","when","interacting","with","an","RL","environment",".","They","can","be","prolonged","and","sliced","and","when","completed",",","allow","to","re-calculate","returns","."]
code: def __repr__(self):
      return repr(
          {
              "timesteps": self._timesteps,
              "last_observation": self._last_observation,
          }
      )
  
imports: import collections
  import os
  import gin
  import gym
  import numpy
  from trax import fastmath
  from trax.rl import advantages
  from trax.supervised import training
label_desc: Use image node_id 3 for calling the Trajectory obj's underlying member method code with example usage: obj.__repr__() and returns: repr