@Override
  protected List<PsiClass> filterTargetClasses(PsiElement element, Project project) {
    return ContainerUtil.filter(super.filterTargetClasses(element, project), 
                                cls -> cls.getContainingClass() == null || cls.hasModifierProperty(PsiModifier.STATIC));
  }
@Override
  protected List<PsiClass> filterTargetClasses(PsiElement element, Project project)