def __repr__(self):
        return "<Requirement(package={package}, version='{version}')>".format(
            package=self.package, version=self.version)
def __init__(self, root, cwd, files, badfn=None):
        super(exactmatcher, self).__init__(root, cwd, badfn)

        if isinstance(files, list):
            self._files = files
        else:
            self._files = list(files)