class_docstr: End-to-end negotiation teacher that loads the data from
  https://github.com/facebookresearch/end-to-end-negotiator.
class_docstr_tok: ["End-to-end","negotiation","teacher","that","loads","the","data","from","https",":","\/\/github.com\/facebookresearch\/end-to-end-negotiator","."]
code: def num_examples(self):
      # 1 example for every expected learner text response (YOU), and 1
      # example for the expected learner final negotiation output values
      num_exs = 0
      dialogues = [
          self._split_dialogue(
              get_tag(episode.strip().split(), DIALOGUE_TAG)
          )
          for episode in self.episodes
      ]
      num_exs = sum(
          len([d for d in dialogue if YOU_TOKEN in d]) + 1
          for dialogue in dialogues
      )
      return num_exs
  
imports: from parlai.core.teachers import Teacher
  from .build import build
  from parlai.utils.io import PathManager
  import os
  import random
label_desc: Use image node_id 2 for calling the NegotiationTeacher obj's underlying member method code with example usage: obj.num_examples() and returns: num_exs