anchor.diff:      property Key : TBooleanDatumKey read FKey;
     end;
   
  -  { TBooleanDataProvider }
  -
     TBooleanDataProvider = class (TmDatasetDataProvider)
     strict private
       FTrueValue : TBooleanDatum;
  
positive.code:     procedure FillVirtualFieldDefs (aFieldDefs : TmVirtualFieldDefs; const aPrefix : String);
    end;
  
  implementation
  
  uses
  
negative.code: begin
    TBooleanDatum.FillVirtualFieldDefs(aFieldDefs, aPrefix);
  end;
  
  
  { TBooleanDatum }
  
  