code: def _package_guildfile(ref):
      matches = _matching_packages(ref)
      if len(matches) == 1:
          _name, gf = matches[0]
          return gf
      if not matches:
          cli.error(
              f"cannot find a package matching '{ref}'\n"
              "Try 'guild packages' for a list of installed packages."
          )
      models_desc = ", ".join([name for name, _gf in matches])
      cli.error(
          f"multiple packages match '{ref}'\n"
          f"Try again with one of these models: {models_desc}"
      )
  
imports: import logging
  import os
  import typing
  from guild import cli
  from guild import click_util
  from guild import config
label_desc: Use image node_id 13 for calling a global function with example usage: _package_guildfile(ref) and returns: gf