1. Download the source code of the framework (one click in IDE) 2. “Find usages” on annotation/annotation properties leads you to init stage, where metamodel i

1. Download the source code of the framework (one click in IDE) 2. “Find usages” on annotation/annotation properties leads you to init stage, where metamodel is usually built 3. “Find usages” on metamodel classes leads you to the implementation of the behavior defined by annotation 4. Run your code with the breakpoint inside the annotated code. Check the stack trace at the breakpoint, look at the methods and fields of the framework classes in it to validate your understanding of how it works from step 3. The RetentionPolicy.SOURCE annotations are handled by an annotation processor at compile time, so it is a bit different, but the general idea is the same.