code: protected synchronized void destroyServerSocket() {
          if (null == this.serverSocket) {
              // already closed
              return;
          }
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "ServerSocket being closed for port " + this.listenPort);
          }
          closeServerSocket();
          this.serverSocket = null;
      }
docs: Destroys the server socket associated with this end point.