return new Promise((resolve, reject) =>{
        console.log('Deleting Columns...');
        var parser = parse({delimiter : ",", quote:'\'});
        var del = new DeleteColumns();
        var temp = bucket.file(fileName);
        var final = bucket.file(fileName.replace('temp', ''));

        //for each row of data
        temp.createReadStream()
        //parse the csv
        .pipe(parser)
        //delete first two columns
        .pipe(del)
        //write to new file
        .pipe(final.createWriteStream()
            .on('finish', function(){
                console.log('Columns Deleted');
                temp.delete();
                resolve();
            })
        );
    });

Deleting Columns...
Columns Deleted

Deleting Columns...
ApiError: No such object: <file> at at Object.parseHttpRespMessage(......)
finished with status: 'crash'