class_docstr: Trigger a callback every `n_steps` timesteps
  
  :param n_steps: (int) Number of timesteps between two trigger.
  :param callback: (BaseCallback) Callback that will be called
      when the event is triggered.
class_docstr_tok: ["Trigger","a","callback","every","`","n_steps","`","timesteps",":","param","n_steps",":","(","int",")","Number","of","timesteps","between","two","trigger",".",":","param","callback",":","(","BaseCallback",")","Callback","that","will","be","called","when","the","event","is","triggered","."]
code: def __init__(self, n_steps: int, callback: BaseCallback):
      super(EveryNTimesteps, self).__init__(callback)
      self.n_steps = n_steps
      self.last_time_trigger = 0
  
imports: import os
  from abc import ABC
  import warnings
  import typing
  from typing import Union, List, Dict, Any, Optional
  import gym
  import numpy
  from stable_baselines.common.vec_env import VecEnv, sync_envs_normalization, DummyVecEnv
  from stable_baselines.common.evaluation import evaluate_policy
  from stable_baselines import logger
label_desc: Use image node_id 1 to create a new EveryNTimesteps object from inherited base classes: EventCallback with example: obj = EveryNTimesteps(n_steps, callback)