def request_seen(self, request):
        fp = self.request_fingerprint(request)
        if self.fingerprints in fp:
            return True
        self.fingerprints.add(fp)
        if self.file:
            self.file.write(fp + os.linesep)
dataset/ETHPy150Open scrapy/scrapy/scrapy/dupefilters.py/RFPDupeFilter.request_seen/swapped operands of `in`