code: def get_experiment_id() -> str:
      """
      Return experiment ID.
      """
      return _experiment_id
  
file_path: nni/nni/trial.py
imports: from __future__ import annotations
  from typing import Any, cast
  from .runtime.env_vars import trial_env_vars
  from .runtime.trial_command_channel import get_default_trial_command_channel
  from .typehint import Parameters, TrialMetric, ParameterRecord
label_desc: Use image node_id 4 for calling a global function with example usage: get_experiment_id() and returns: _experiment_id