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","."]
docstr: Returns a `Trajectory` with the last `length` observations.
docstr_tok: ["Returns","a","`","Trajectory","`","with","the","last","`","length","`","observations","."]
code: def suffix(self, length):
      """Returns a `Trajectory` with the last `length` observations."""
      assert length >= 1
      t = Trajectory(self._last_observation)
      t._timesteps = self._timesteps[
          -(length - 1) :
      ]  # pylint: disable=protected-access
      return t
  
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 4 for calling the Trajectory obj's underlying member method code with example usage: obj.suffix(length) and returns: t