code: def get_current_parameter(tag: str | None = None) -> Any:
      global _params
      if _params is None:
          return None
      if tag is None:
          return _params["parameters"]
      return _params["parameters"][tag]
  
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 3 for calling a global function with example usage: get_current_parameter(tag) and returns: _params, None, _params