def frozencopy(self):
        copy = self.copy()
        copy.freeze()
        return copy
Netstrings that have no leading digits nor a colon are
dataset/ETHPy150Open scrapy/scrapy/scrapy/settings/__init__.py/BaseSettings.frozencopy--crossover with--dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/test/test_protocols.py/NetstringReceiverTestCase.test_missingNumberAndColon