code: @Override
      public void close() {
          ((ForkProtocolStack)prot_stack).remove(fork_channel_id);
          if(state == State.CLOSED)
              return;
          disconnect();  // leave cluster if connected
          prot_stack.destroy();
          state=State.CLOSED;
          notifyChannelClosed(this);
      }
docs: Closes the fork-channel, essentially setting its state to CLOSED. Note that - contrary to a regular channel -
  a closed fork-channel can be connected again: this means re-attaching the fork-channel to the main-channel