/// <summary>Returns true if the original value for the field with the fieldIndex passed in, read from the persistent storage was NULL, false otherwise. /// Should not be used for testing if the current value is NULL, use <see cref="TestCurrentFieldValueForNull"/> for that.</summary> /// <param name="fieldIndex">Index of the field to test if that field was NULL in the persistent storage</param> /// <returns>true if the field with the passed in index was NULL in the persistent storage, false otherwise</returns> public bool TestOriginalFieldValueForNull(MessageUserActivityFieldIndex fieldIndex) { return(base.Fields[(int)fieldIndex].IsNull); }