Не запускается gulp browser-sync

assert.js:42
throw new errors.AssertionError({
^
AssertionError [ERR_ASSERTION]: Task function must be specified
at Gulp.set [as _setTask] (/home/просто/путь/к проекту/bc/node_modules     /undertaker/lib/set-task.js:10:3)
at Gulp.task (/home/просто/путь/к проекту/node_modules/undertaker/lib/task.js:13:8)
at Object.<anonymous> (/home/просто/путь/к проекту/gulpfile.js:23:6)
at Module._compile (module.js:652:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)
at tryModuleLoad (module.js:505:12)
at Function.Module._load (module.js:497:3)
at Module.require (module.js:596:17)
at require (internal/module.js:11:18)

Вот делаю по оф докам.

https://browsersync.io/docs/gulp#gulp-install

var gulp        = require('gulp');
var browserSync = require('browser-sync').create();
// Static server
gulp.task('browser-sync', function() {
   browserSync.init({
    server: {
        baseDir: "./"
    }
  });
});