@classmethod
def remove_label(cls, group):
    """ Remove an existing label

        The goal of this function is to remove an existing label of a specific
        group::

            @Configuration.add('create-db', label="Name of the group")
            def bar(parser, defaul):
                pass

            Configuration.remove_label('create-db')

        :param group: group is a set of parser option
        """
    if group in cls.labels:
        del cls.labels[group]
