@NotNull
@Override
protected Collection<PsiReference> resolveOuterReferences(PsiElement psiElement) {
    Collection<PsiReference> result = new ArrayList<>();
    if (!(psiElement instanceof PsiJavaFile)) {
        return result;
    }
    PsiClass[] classes = ((PsiJavaFile) psiElement).getClasses();
    for (PsiClass psiClass : classes) {
        result.addAll(ReferencesSearch.search(psiClass, GlobalSearchScopes.projectProductionScope(getProject())).findAll());
    }
    return result;
}
 

@NotNull
@Override
protected Collection<PsiReference> resolveOuterReferences(PsiElement callee) {
    return ReferencesSearch.search(callee, GlobalSearchScopes.projectProductionScope(getProject())).findAll();
}