def __repr__(self):
        return "<NamedRequirements({}{})>".format(
            self.name,
            ", filename='{}'".format(self.filename.name) if self.filename
            else "")
def warn(txt, act, opt):
    if opt.get('display_examples'):
        print(txt + ":\n" + str(act))
    else:
        warn_once(txt)