npm run build
> gulp build
assert.js:374
throw err;
^
AssertionError [ERR_ASSERTION]: Task function must be specified
at Gulp.set [as _setTask] (/Users/om/Desktop/ej2-react-samples-master/node_modules/undertaker/lib/set-task.js:10:3)
at Gulp.task (/Users/om/Desktop/ej2-react-samples-master/node_modules/undertaker/lib/task.js:13:8)
at Object.<anonymous> (/Users/om/Desktop/ej2-react-samples-master/gulpfile.js:363:6)
at Module._compile (internal/modules/cjs/loader.js:956:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:973:10)
at Module.load (internal/modules/cjs/loader.js:812:32)
at Function.Module._load (internal/modules/cjs/loader.js:724:14)
at Module.require (internal/modules/cjs/loader.js:849:19)
at require (internal/modules/cjs/helpers.js:74:18)
at execute (/Users/om/Desktop/ej2-react-samples-master/node_modules/gulp/node_modules/gulp-cli/lib/versioned/^4.0.0/index.js:36:18) {
generatedMessage: false,
code: 'ERR_ASSERTION',
actual: false,
expected: true,
operator: '=='
}