recipe browserify-transforms is broken

The [recipe browserify-transforms](https://github.com/gulpjs/gulp/blob/master/docs/recipes/browserify-transforms.md) recipe contains this line:

.pipe(source('app.js', { sourcemaps: true }))

It's wrong, source is the vinyl-source-stream plugin and does not take such second parameter. I think the author supposed it to be gulp.src() but it is not. I think it was an attempt to use the built-in sourcemap support instead of the gulp-sourcemaps plugin, but it doesn't work as written.
I don't know how to rewrite the example using the built-in sourcemap support (is it doable at all?)