code: def prepare_context_and_role(runner, ctx, role, sub_ctx_name):
      sub_ctx = ctx.sub_ctx(sub_ctx_name)
      runner.set_context(sub_ctx)
      runner.set_role(role)
  
file_path: FATE/python/fate/components/components/nn/component_utils.py
imports: from fate.components.components.nn.loader import Loader
  from fate.components.components.nn.nn_runner import NNRunner
  from fate.components.components.utils import consts
  from fate.arch.dataframe import DataFrame
  from fate.components.components.utils.tools import add_dataset_type
  from fate.arch import Context
  from fate.components.core import ARBITER, GUEST, HOST, Role, cpn
  import logging
  from fate.components.core.component_desc.artifacts.data._dataframe import DataframeReader, DataframeWriter
  from fate.components.core.component_desc.artifacts.data._directory import DataDirectoryReader
  from fate.components.core.component_desc.artifacts.model._directory import ModelDirectoryReader, ModelDirectoryWriter
label_desc: Use image node_id 2 for calling a global function with example usage: prepare_context_and_role(runner, ctx, role, sub_ctx_name) without return types