code: def put(self, key, value):
          
  
          self.maybe_clean()
          self.data[key] = value
docs: Associate key and value in the cache.
          @param key: the key
          @type key: (dns.name.Name, int, int) tuple whose values are the
          query name, rdtype, and rdclass.
          @param value: The answer being cached
          @type value: dns.resolver.Answer object