class_docstr: The dev and test set are the same, but the training set has been augmented using the
  other utterances.
  
  Moreover, only 16 candidates are used (including the right one)
code: def get_nb_cands(self):
      return 16
  
imports: from parlai.core.teachers import FixedDialogTeacher
  from parlai.utils.io import PathManager
  from .build import build
  import json
  import os
  import random
label_desc: Use image node_id 2 for calling the DSTC7TeacherAugmentedSampled obj's underlying member method code with example usage: obj.get_nb_cands() and returns: int