static @Nullable ModCommandAction createFix(@NotNull PsiClass parentClass, @NotNull PsiClass subclass) {
    if (!parentClass.hasModifierProperty(PsiModifier.SEALED) || !parentClass.getManager().isInProject(parentClass)) return null;
    boolean parentIsInterface = parentClass.isInterface();
    if (parentIsInterface && (subclass.isRecord() || subclass.isEnum())) return null;
    PsiModifierList modifiers = subclass.getModifierList();
    if (modifiers == null || hasSealedClassSubclassModifier(modifiers)) return null;
    return new ExtendSealedClassFix(parentClass, subclass);
  }
static @Nullable ModCommandAction createFix(@NotNull PsiClass parentClass, @NotNull PsiClass subclass)