public static Pair<PsiExpression, Nullability> getNullabilityFromFieldInitializers(PsiField field) {
    if (DfaPsiUtil.isFinalField(field) && PsiAugmentProvider.canTrustFieldInitializer(field)) {
      PsiExpression initializer = field.getInitializer();
      if (initializer != null) {
        return Pair.create(initializer, getExpressionNullability(initializer));
      }

      List<PsiExpression> initializers = DfaPsiUtil.findAllConstructorInitializers(field);
      if (initializers.isEmpty()) {
        return Pair.create(null, Nullability.UNKNOWN);
      }

      for (PsiExpression expression : initializers) {
        Nullability nullability = getExpressionNullability(expression);
        if (nullability == Nullability.NULLABLE) {
          return Pair.create(expression, Nullability.NULLABLE);
        }
      }

      if (DfaPsiUtil.isInitializedNotNull(field)) {
        return Pair.create(ContainerUtil.getOnlyItem(initializers), Nullability.NOT_NULL);
      }
    }
    else if (isOnlyImplicitlyInitialized(field)) {
      return Pair.create(null, Nullability.NOT_NULL);
    }
    return Pair.create(null, Nullability.UNKNOWN);
  }
public static Pair<PsiExpression, Nullability> getNullabilityFromFieldInitializers(PsiField field)