code: def get_default_run_options():
      """Create a default run option."""
      run_options = config_pb2.RunOptions()
      # Force every worker session to use different collective graph keys,
      # thus to make session run has different TensorFlow step_ids when fetching collective_op.
      # A different step_id avoids skipping re-initialization of a rendezvous object.
      # Shared step_id may cause racing for different sessions, across which some variable is shared.
      # For more information, please refer to TensorFlow worker.proto: `collective_graph_key`
      run_options.experimental.collective_graph_key = (
          int(
              hashlib.md5(ENV.AUTODIST_WORKER.val.encode()).hexdigest(),
              16,
          )
          % MAX_INT32
      )
      # run_options.trace_level = config_pb2.RunOptions.FULL_TRACE
      return run_options
  
file_path: autodist/autodist/runner.py
imports: import hashlib
  import os
  from tensorflow.core.protobuf import config_pb2, rewriter_config_pb2
  from tensorflow.python.client import timeline, session
  import autodist.autodist
  import autodist.const
  from autodist.const import ENV, MAX_INT32
  from autodist.utils import logging
label_desc: Use image node_id 2 for calling a global function with example usage: get_default_run_options() and returns: run_options