anchor.diff:  constructor TNullableBoolean.Create(aValue: Boolean);
   begin
     inherited Create;
  -  FValue := aValue;
  +  SetValue(aValue);
   end;
   
   procedure TNullableBoolean.Assign(const aSource: TNullableBoolean);
  
positive.code: constructor TNullableColor.Create(aValue: TColor);
  begin
    inherited Create;
    FValue := aValue;
  end;
  
  procedure TNullableColor.Assign(const aSource: TNullableColor);
  
negative.code: constructor TNullableString.Create(aValue: String);
  begin
    inherited Create;
    SetValue(aValue);
  end;
  
  procedure TNullableString.Assign(const aSource: TNullableString);
  