Gulp Closure Compiler - using closure library

gulpfile.js

// As of this writing, the example on https://github.com/steida/gulp-closure-compiler doesn't
//   explain how to compile your project using Google's Closure Library.
// Since the newest version of the compiler doesn't need a deps file anymore, we just need
//   to provide all our module definitions (files with goog.provide) to the task src.
gulp.task('build', function () {

    // Specify where your Closure Library is stored --------------------------vvvv
    gulp.src(['main.js', 'src/**/*.js', 'node_modules/closure-library/closure/goog/**/*.js'])

        // Everything else is the same as in the docs
        .pipe(closureCompiler({
            compilerPath: '/usr/local/google-closure/compiler.jar',
            fileName: 'dist/build.js',
            compilerFlags: {
                closure_entry_point: 'rokko.main',
                compilation_level: 'ADVANCED_OPTIMIZATIONS',
                define: [
                    "goog.DEBUG=false"
                ],
                only_closure_dependencies: true,
                warning_level: 'VERBOSE',
                create_source_map: 'app.comp.js.map'
            }
        }));
});