Generation with newest xtext and 2.9.2 does not work cause testing

[cdietrich]

Generation with newest xtext and 2.9.2 does not work cause testing
useDeprecatedClasses flag not there on 2.9.2

[cdietrich]

i dont see any way how this can be resolved to work with multiple versions

[cdietrich]

we could have a custom fragment that uses reflection to switch to the old generation