def GetPatchMetadata(patch_dict):
  """Gets the patch's metadata.

  Args:
    patch_dict: A dictionary that has the patch metadata.

  Returns:
    A tuple that contains the metadata values.
  """

  # Get the metadata values of a patch if possible.
  start_version = patch_dict.get('start_version', 0)
  end_version = patch_dict.get('end_version', None)
  is_critical = patch_dict.get('is_critical', False)

  return start_version, end_version, is_critical