public boolean isNotNull(@NotNull PsiModifierListOwner owner, boolean checkBases) {
    NullabilityAnnotationInfo info = findEffectiveNullabilityInfo(owner);
    return info != null && info.getNullability() == Nullability.NOT_NULL && (checkBases || info.getInheritedFrom() == null);
  }
public boolean isNotNull(@NotNull PsiModifierListOwner owner, boolean checkBases)