anchor.diff:    TNullableString = class;
     TNullableDouble = class;
     TNullableInteger = class;
  +  TNullableBoolean = class;
   
     { TNullableStringRecord }
   
  
positive.code: uses
    SysUtils {$IFDEF FPC}, LazUtf8{$ENDIF};
  
  { TNullableIntegerRecord }
  
  procedure TNullableIntegerRecord.SetNull;
  
negative.code:     tmpInt := aValue;
      SetValue(tmpInt);
    end;
  end;
  
  procedure TNullableIntegerRecord.Assign(const aSource: TNullableInteger);
  