How to use the event-stream.merge function in event-stream

gulp.task('build', function (done) {
    gulp_util.log('Building source files');

    es
        .merge(Object.keys(sources).map(function (n) {
            return build_app_sources(n, true);
        }))
        .pipe(es.wait(function (err, body) {
            gulp_util.log('Collecting static files');
            run('./manage.py collectstatic --noinput')
                .exec('', function (err) { done(err); });
        }));
});

gulp.task('build-prod', ['build.lib'], function () {
    var tsProject = typescript.createProject('./tsconfig.json', { typescript: require('typescript') });
    var tsSrcInlined = gulp.src([webroot + '**/*.ts'], { base: webroot })
        .pipe(inlineNg2Template({ base: webroot }));
    return eventStream.merge(tsSrcInlined, gulp.src('Typings/**/*.ts'))
        .pipe(sourcemaps.init())
        .pipe(typescript(tsProject))
        .pipe(sourcemaps.write())
        .pipe(gulp.dest(webroot));
});

gulp.task('bundle', function () {
    tagsStream = gulp.src('./src/**/*.tag')
        .pipe(riot({brackets:'{{ }}'}));
    es6Stream = gulp.src('./src/**/*.es6');
    eventStream.merge(tagsStream, es6Stream)
        .pipe(concat('riot-mui.js'))
        .pipe(babel({presets:['es2015']}))
        .pipe(minify())
        .pipe(sourcemaps.write())
        .pipe(gulp.dest('./build/js'));
});

gulp.task('js', function(){
	var jssrc = gulp.src((env.p) ? 'src/js/**/*.js' : ['src/js/**/*.js', '!src/js/analytics.js']);
	var tssrc = gulp.src(['src/js/**/*.ts'])
		.pipe(ts({
			noImplicitAny: true,
			target: 'es5',
			lib: ['dom', 'scripthost', 'es5', 'es2015.core'],
			module: 'commonjs'
		}));
	return merge(jssrc, tssrc)
		.pipe(plumber())
		.pipe(concat('main.js'))
		.pipe(uglify())
		.pipe(gulp.dest('assets/js/'));
});

gulp.task("default", function() {
  eventStream
    .merge(
      gulp.src("almond.js"),
      gulp
        .src("*.js")
        .pipe(amdOptimize("main"))
        .pipe(concat("main-bundle-modules.js"))
    )
    .pipe(order(["almond.js", "main-bundle-modules.js"]))
    .pipe(concat("main-bundle.js"))
    .pipe(gulp.dest("."));
});