class_docstr: vector of envs to support vector reset and vector step.
  `vector_step` api will automatically reset envs which are done.
docstr: Args:
      envs: List of env
docstr_tok: ["Args",":","envs",":","List","of","env"]
code: def __init__(self, envs):
      """
      Args:
          envs: List of env
      """
      self.envs = envs
      self.envs_num = len(envs)
  
imports: import six
  from collections import defaultdict
label_desc: Use image node_id 1 to create a new VectorEnv object from inherited base classes: object with example: obj = VectorEnv(envs)