How to use the cson.parseJSONString function in cson

var processJSON2CSON = function (data, sourceFileName, targetFileName, writer) {
    data = CSON.parseJSONString(data);

    if (typeof data === 'Error') {
        var err = "CSON: Invalid JSON content found";

        writer.write(JSON.stringify({
            Success: false,
            SourceFileName: sourceFileName,
            TargetFileName: targetFileName,
            Remarks: err,
            Details: err,
            Errors: [{
                Message: err,
                FileName: sourceFileName
            }]
        }));
        writer.end();