def __repr__(self):
        return "<Requirement(package={package}, version='{version}')>".format(
            package=self.package, version=self.version)
def __init__(self, matchers):
        m1 = matchers[0]
        super(unionmatcher, self).__init__(m1._root, m1._cwd)
        self.traversedir = m1.traversedir
        self._matchers = matchers