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 test_should_encode_map(self):
        encoded = cypher_repr(OrderedDict([("one", 1), ("two", 2.0), ("number three", u"three")]))
        assert encoded == u"{one: 1, two: 2.0, `number three`: 'three'}"