Qt Touchscreen calibration how to use QWSCalibratedMouseHandler sendFiltered

Hi there,
i am using this example to calibrate my Touchscreen, this works fine so far.
Now i recognize some noisy pointer when touching the touchscreen.
I have seen that QWSCalibratedMouseHandler has some Functions like setFilterSize and sendFiltered i would like to use them but i'm not aware of how to do this ?
I think the example just uses QWSMouseHandler where i dont have these filter functionality.

So how can i use the Filter functions provided by QWSCalibratedMouseHandler ?
thx
drquade