code: def n_roles(self):
      return self._n_workers + self._n_ps
  
imports: import os
  import json
  from typing import Any, BinaryIO, Dict, List, Optional, TextIO, Union
  import numpy
  from ....None import opcodes
  from ....core import recursive_tile
  from ....core.context import get_context
  from ....remote.run_script import RunScript, _extract_inputs
  from ....serialization.serializables import BytesField, Int32Field, DictField, StringField
  from ....typing import SessionType, TileableType
  from ....utils import to_binary
  from ...utils import collect_ports
  from ..utils import pick_workers
label_desc: Use image node_id 4 for calling the RunTensorFlow obj's underlying member method code with example usage: obj.n_roles() and returns: unknown