code: def parser_diff_prefix():
      """Return an instance of `OrionCmdlineParser` with a different config prefix."""
      return OrionCmdlineParser(
          config_prefix="config2", allow_non_existing_files=True
      )
  
imports: import os
  from pathlib import Path
  from typing import Any, List, NamedTuple, Optional, Tuple
  import pytest
  from orion.core.io.convert import JSONConverter
  from orion.core.io.orion_cmdline_parser import OrionCmdlineParser
  from orion.core.worker.experiment import Experiment
  from orion.core.worker.trial import Trial
label_desc: Use image node_id 3 for calling a global function with example usage: parser_diff_prefix() and returns: OrionCmdlineParser