Method close

src/test/msgr/test_async_networkstack.cc:833–838

      center->dispatch_event_external(&read_ctxt);
    }
    void close() {
      ASSERT_FALSE(write_enabled);
      socket.shutdown();
      center->delete_file_event(socket.fd(), EVENT_READABLE);
      center->dispatch_event_external(new C_delete<Server>(this));
    }
    void do_read_request() {
      if (dead)
        return ;