class_docstr: World for recording a turker's question and answer given a context.
  
  Assumes the context is a random context from a given task, e.g. from SQuAD, CBT,
  etc.
code: def episode_done(self):
      return self.episodeDone
  
file_path: ParlAI/parlai/crowdsourcing/tasks/qa_data_collection/worlds.py
imports: from parlai.crowdsourcing.utils.worlds import CrowdTaskWorld
  from parlai.core.worlds import validate
label_desc: Use image node_id 3 for calling the QADataCollectionWorld obj's underlying member method code with example usage: obj.episode_done() and returns: self