anchor.diff:  procedure DValueSetAsBoolean(ADValue:PDRawValue; pvValue:Boolean);
   function DValueGetAsBoolean(ADValue: PDRawValue): Boolean;
   
  +function DValueIsEmpty(ADValue:PDRawValue): Boolean;
  +
   procedure RawValueCopyFrom(pvSource, pvDest: PDRawValue; pvIgnoreValueTypes:
       TDValueDataTypes = [vdtInterface, vdtObject, vdtPtr]);
   
  
positive.code:     // Valueķʷװ, ֱӷValue.AsXXXX
      procedure BindObject(pvObject: TObject; pvFreeAction: TObjectFreeAction =
          faFree);
  
  
  
  
negative.code: 
      procedure BindObject(pvObject: TObject; pvFreeAction: TObjectFreeAction =
          faFree);
          
      /// <summary>
      ///   ַգnull
      /// </summary>
      function IsEmpty: Boolean;
  
  
      /// <summary>
  