public object?GetNthMask(int index)
            {
                ObjectBounds_FieldIndex enu = (ObjectBounds_FieldIndex)index;

                switch (enu)
                {
                case ObjectBounds_FieldIndex.First:
                    return(First);

                case ObjectBounds_FieldIndex.Second:
                    return(Second);

                default:
                    throw new ArgumentException($"Index is out of range: {index}");
                }
            }
            public void SetNthMask(int index, object obj)
            {
                ObjectBounds_FieldIndex enu = (ObjectBounds_FieldIndex)index;

                switch (enu)
                {
                case ObjectBounds_FieldIndex.First:
                    this.First = (Exception?)obj;
                    break;

                case ObjectBounds_FieldIndex.Second:
                    this.Second = (Exception?)obj;
                    break;

                default:
                    throw new ArgumentException($"Index is out of range: {index}");
                }
            }