wStream = require("stream").Writable

logStream = function logStream () {
                    this.file = logfile;
                    wStream.call(this);
                };

    require("util").inherits(logStream, wStream);
    logStream.prototype._write = function logStream_write (data, enc, cb) {
        fs.appendFile(this.file, data, 'utf-8', function WatchLogErr(err) {
           if (err) {throw Error(err);}
        });

const log = new logStream();

log.on('finish', function () {
        console.log("finished writing to log stream");
    });

log.write("watching changesn");
log.write("watching changesn");