docs: def ImportConfig(filename, config):
    """Reads an old config file and imports keys and user accounts."""
    sections_to_import = ["PrivateKeys"]
    entries_to_import = [
        "Client.executable_signing_public_key", "CA.certificate",
        "Frontend.certificate"
    ]
    options_imported = 0
    old_config = grr_config.CONFIG.MakeNewConfig()
    old_config.Initialize(filename)
  
    for entry in old_config.raw_data:
      try:
        section = entry.split(".")[0]
        if section in sections_to_import or entry in entries_to_import:
          config.Set(entry, old_config.Get(entry))
          print("Imported %s." % entry)
          options_imported += 1
  
      except Exception as e:  # pylint: disable=broad-except
        print("Exception during import of %s: %s" % (entry, e))
    return options_imported