fix vis-tests with strict errors
fix vis-tests with strict errors

RaananW/Babylon.js,sebavan/Babylon.js,RaananW/Babylon.js,RaananW/Babylon.js,BabylonJS/Babylon.js,BabylonJS/Babylon.js,BabylonJS/Babylon.js,sebavan/Babylon.js,sebavan/Babylon.js