code: def want_dnssec(self, wanted=True):
          
          if wanted:
              if self.edns < 0:
                  self.use_edns()
              self.ednsflags |= dns.flags.DO
          elif self.edns >= 0:
              self.ednsflags &= ~dns.flags.DO
docs: Enable or disable 'DNSSEC desired' flag in requests.
          @param wanted: Is DNSSEC desired?  If True, EDNS is enabled if
          required, and then the DO bit is set.  If False, the DO bit is
          cleared if EDNS is enabled.
          @type wanted: bool