def __init__(self, name, filename=None):
        self.name = name
        super(NamedRequirements, self).__init__(filename=filename)
def current_label_start(self):
        if self.current_label and self.message:
            return self.message.get_label_range(self.current_label, self.proto_view, False)[0]
        else:
            return -1