private @Nullable PsiClass getReferencedClass() {
        LOG.assertTrue(getParent() instanceof PsiAnnotationParameterList && getParent().getParent() instanceof PsiAnnotation);
        PsiAnnotation annotation = (PsiAnnotation)getParent().getParent();
        PsiJavaCodeReferenceElement nameRef = annotation.getNameReferenceElement();
        if (nameRef == null) return null;
        PsiElement target = nameRef.resolve();
        return target instanceof PsiClass ? (PsiClass)target : null;
      }
private @Nullable PsiClass getReferencedClass()