def __repr__(self):
        return "<Requirement(package={package}, version='{version}')>".format(
            package=self.package, version=self.version)
def badmatch(match, badfn):
    """Make a copy of the given matcher, replacing its bad method with the given
    one.
    """
    m = copy.copy(match)
    m.bad = badfn
    return m