def find_rdataset(self, rdclass, rdtype, covers=dns.rdatatype.NONE,
                      create=False):

        for rds in self.rdatasets:
            if rds.match(rdclass, rdtype, covers):
                return rds
        if not create:
            raise KeyError
        rds = dns.rdataset.Rdataset(rdclass, rdtype)
        self.rdatasets.append(rds)
        return rds
Find an rdataset matching the specified properties in the
dataset/ETHPy150Open catap/namebench/nb_third_party/dns/node.py/Node.find_rdataset