void findAnnotationsPresent() {
            ComputeAnnotationSet annotationComputer = new ComputeAnnotationSet(elementUtils);
            // Use annotation processing to compute the set of annotations present
            annotationsPresent = new LinkedHashSet<TypeElement>();
            for (ClassSymbol classSym : topLevelClasses)
                annotationComputer.scan(classSym, annotationsPresent);
            for (PackageSymbol pkgSym : packageInfoFiles)
                annotationComputer.scan(pkgSym, annotationsPresent);
        }