Introductory document 05-2 use return instructions the current task has been completed

const { src, dest, series, watch, parallel } = require("gulp");function clean(cb) {console.log('clean up dist');cb();}function js(){console.log('Process js, use return to indicate that the current task has been completed');return src('*.js')}function css(cb){console.log('processing css');cb();}function img(cb){console.log('processing img');cb();}function build(cb) {console.log('Packaging');cb();}exports.default = series(clean,js,css,img,build);