code: def num_episodes(self):
      return len(self.episodes)
  
file_path: ParlAI/parlai/tasks/dream/agents.py
imports: from parlai.core.teachers import FixedDialogTeacher
  from parlai.utils.io import PathManager
  from .build import build
  import os
  import json
label_desc: Use image node_id 6 for calling the DREAMTeacher obj's underlying member method code with example usage: obj.num_episodes() and returns: len