code: def if_installed(version_or_none: str | None) -> str:
      """helper method to optionally return module version number or not installed
  
      :param version_or_none:
      :return:
      """
      return version_or_none or "(not installed)"
  
file_path: bokeh/src/bokeh/command/subcommands/info.py
imports: from __future__ import annotations
  import logging
  import platform
  import sys
  from argparse import Namespace
  from bokeh import __version__
  from bokeh.settings import settings
  from bokeh.util.compiler import nodejs_version, npmjs_version
  from bokeh.util.dependencies import import_optional
  from ..subcommand import Argument, Subcommand
label_desc: Use image node_id 1 for calling a global function with example usage: if_installed(version_or_none) and returns: unknown