def loads(self, requirements_text):
        lines = re.findall(Requirement.spec_regex,
                           requirements_text,
                           re.MULTILINE)
        for line in lines:
            self.add(Requirement(line[0], "".join(line[1:])))
def encode(self):
        if self.version == 6:
            return {'ip6': self.ip_addr}
        else:
            return {'ip4': self.ip_addr}