anchor.diff:      (unwind-protect-case ()
           (progn
             (setf (iolib.streams:fd-non-blocking socket) t)
  -          (add-socket socket)
             (iomux:set-io-handler *event-base*
                                   (iolib.sockets:socket-os-fd socket)
                                   :read
  
positive.code: 
  (defun close-socket (socket)
    (let ((fd (iolib.sockets:socket-os-fd socket)))
      (ignore-errors (iomux:remove-fd-handlers *event-base* fd))
      (remove-socket socket)
      (close socket)))
  
  
negative.code:                 (progn
                    (setf *event-base* (make-instance 'iomux:event-base))
                    (with-open-stream (sock (start-echo-server host port))
                      (declare (ignore sock))
                      (iomux:event-dispatch *event-base* :timeout timeout)))
               (close-all-sockets)
               (close *event-base*))))
  