class_docstr: Do NOT use this directly, use its children.
class_docstr_tok: ["Do","NOT","use","this","directly",",","use","its","children","."]
docstr: For determining the key to read the NUM_SAMPLES.
code: def _teacher_type(self):
      """
      For determining the key to read the NUM_SAMPLES.
      """
      raise NotImplementedError(
          "Teachers inheriting from BaseBB3DataTeacher "
          "must implement their own _teacher_type function."
      )
  
imports: import os
  import json
  from copy import deepcopy
  from parlai.core.message import Message
  from parlai.utils.data import DatatypeHelper
  from parlai.core.teachers import ChunkTeacher
  from .build import build
label_desc: Use image node_id 6 for calling the BaseBB3DataTeacher obj's underlying member method code with example usage: obj._teacher_type() without return types