code: def connect(self, src, dst=None, callback=None):
          '''
          :param src: source node, if dst is None it will be destination node and the root (dummy) node will be source
          :param dst: destination node (default: None)
          :type callback: func(fuzzer, edge, response) -> None
          :param callback: a function to be called after the response for src received and before dst is sent
          '''
          assert src
          if dst is None:
              dst = src
              src = self._root
          src_id = src.hash()
          dst_id = dst.hash()
          if src_id not in self._graph:
              raise KittyException('source node id (%#x) (%s) is not in the node list ' % (src_id, src))
          self._graph[src_id].append(Connection(src, dst, callback))
          if dst_id not in self._graph:
              self._graph[dst_id] = [f connect(self, src, dst=None, callback=None):
          '''
          :param src: source node, if dst is None it will be destination node and the root (dummy) node will be source
          :param dst: destination node (default: None)
          :type callback: func(fuzzer, edge, response) -> None
          :param callback: a function to be called after the response for src received and before dst is sent
          '''
          assert src
          if dst is None:
              dst = src
              src = self._root
          src_id = src.hash()
          dst_id = dst.hash()
          if src_id not in self._graph:
              raise KittyException('source node id (%#x) (%s) is not in the node list ' % (src_id, src))
          self._graph[src_id].append(Connection(src, dst, callback))
          if dst_id not in self._graph:
              self._graph[dst_id] = []
docs: :param src: source node, if dst is None it will be destination node and the root (dummy) node will be source
          :param dst: destination node (default: None)
          :type callback: func(fuzzer, edge, response) -> None
          :param callback: a function to be called after the response for src received and before dst is sent