def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def __eq__(self, other):
        if isinstance(other, self.__class__):
            return self.ip_addr == other.ip_addr
        elif hasattr(other, "ip4") and hasattr(other, "ip6"):
            # vl_api_address_union_t
            if 4 == self.version:
                return self.ip_addr == other.ip4
            else:
                return self.ip_addr == other.ip6
        else:
            raise Exception("Comparing VppIpAddressUnions:%s"
                            " with incomparable type: %s",
                            self, other)