Function setTimeout

setTimeout(cb, delay?, ...args): number
Sets a timer which executes a function once after the delay (in milliseconds) elapses. Returns an id which may be used to cancel the timeout.

note: only js2.0 support
```
setTimeout(() => { console.log('hello'); }, 500);
```
Parameters
- cb: ((...args) => void)
  callback function to execute when timer expires
  - - (...args): void
    - Parameters
      Rest ...args: any[]
      Returns void
- Optional delay: number
  delay in ms
- Rest ...args: any[]
  arguments passed to callback function
Returns number