How can i use "refreshScreen(incremental=1)" while controlling mouse and keyboard in my vnc client

[1475165459]

• VNC server and version
  protocol: 3.8.0 on MacOS

• vncdotool version
  1.0.0

• steps to reproduce
  I want to refresh screen while controlling mouse and keyboard,it's ok for me when i use refreshScreen(incremental=0),but i found that it will take up a lot of network,so i set incremental to 1 as it will only refresh while screen changed.
  It works fine if i only refresh the screen,but when i move the mouse,it won't work and will just hang there until the screen changed.
  So here's the issue,how can i use "refreshScreen(incremental=1)" while controlling mouse and keyboard, thanks.