Returns the registered member class for the given resource.

    :param resource: registered resource
    :type resource: class implementing or instance providing or subclass of
        a registered resource interface.

def get_member_class(resource):
    """
    Returns the registered member class for the given resource.

    :param resource: registered resource
    :type resource: class implementing or instance providing or subclass of
        a registered resource interface.
    """
    reg = get_current_registry()
    if IInterface in provided_by(resource):
        member_class = reg.getUtility(resource, name='member-class')
    else:
        member_class = reg.getAdapter(resource, IMemberResource,
                                      name='member-class')
    return member_class