class_docstr: Utility class for iterating through a single episode.
  
  Used in the context of the Conversations class.
class_docstr_tok: ["Utility","class","for","iterating","through","a","single","episode",".","Used","in","the","context","of","the","Conversations","class","."]
code: def __len__(self):
      return len(self.turns)
  
imports: import datetime
  import json
  import os
  import itertools
  from parlai.utils.io import PathManager
  from parlai.core.metrics import dict_report
  from parlai.utils.misc import AttrDict
  import parlai.utils.logging
label_desc: Use image node_id 4 for calling the Conversation obj's underlying member method code with example usage: obj.__len__() and returns: len