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 __init__(self, path=None, resolver=None):
        self._path = path or ()
        if not resolver:
            resolver = Resolver()
        self._resolver = resolver