anchor.diff:      Procedure ValueArray(Const name : String); override;
       Procedure FinishArray; override;
       Procedure ValueInArray(Const value : String); overload; override;
  +    procedure valueNullInArray; override;
     End;
   
     TCanonicalJsonNodeType = (jntProperty, jntObject, jntArray);
  
positive.code:     ValueNullInArray
    Else
      FCache := JSONString(value);
  end;
  
  procedure TJsonWriterDirect.FinishObject;
  
negative.code: 
  procedure TJSONWriter.ValueNullInArray;
  begin
    raise Exception.Create('Need to override '+className+'.ValueNullInArray');
  end;
  
  procedure TJSONWriter.ValueNumber(const name, avalue: String);
  