private static boolean isNotNullNotInferred(@NotNull PsiModifierListOwner owner, boolean checkBases, boolean skipExternal) {
    Project project = owner.getProject();
    NullableNotNullManager manager = NullableNotNullManager.getInstance(project);
    NullabilityAnnotationInfo info = manager.findEffectiveNullabilityInfo(owner);
    if (info == null || info.isInferred() || info.getNullability() != Nullability.NOT_NULL) return false;
    if (!checkBases && info.getInheritedFrom() != null) return false;
    if (skipExternal && info.isExternal()) return false;
    return true;
  }
private static boolean isNotNullNotInferred(@NotNull PsiModifierListOwner owner, boolean checkBases, boolean skipExternal)