code: @Override
    public synchronized void release(Integer port) {
      if(port != null){
        portsInUse.remove(port);
        if (port >= minPort && port <= maxPort && isEvenNumber(port)) {
          availablePorts.add(port);
        }
      }
    }
docs: /* (non-Javadoc)
  @see io.selendroid.server.model.impl.EmulatorPortFinder#release(java.lang.Integer)