I was going through https://help.hybris.com/6.0.0/hcd/8b6ded0d86691014a6fab18e171c1f91.html to understand build framework of hybris. Here it is written that model classes is generated during preparation phase of build. Again later on it is written that Model classes are generated during building extension phase. I am confused . Exactly when model classes ,Jalo classes are generated during build.