@classmethod
def _ap_compute_external_class_name_from_concrete_class(cls, a_type):
    """
        Return the string value of the external class name.

        By default this will be either the value of
        ``__external_class_name__`` or, if not found, the value of
        ``__name__``.

        Subclasses may override.
        """
    return getattr(a_type, '__external_class_name__', a_type.__name__)
