Can someone please explain what PHP "with" does? 

**Example begins:**

Say I have a class:

`\App\fa_batch`

*What is the difference between this statement:*

```
$w = (with (new \App\fa_batch))
       // uses 'with'
       // returns App\fa_batch 

```

*and this statement?*

```
$n = (new \App\fa_batch)
       // does not use 'with'
       // also returns App\fa_batch 

```

**Context / Background Info:**

I'm having trouble finding documentation for `with`, maybe because the PHP.net, stack overflow and google search engines considers `php "with" keyword` such a common search phrase.

If context helps, I came across this usage of the word `with` from this answer: 
<https://stackoverflow.com/a/33222754/5722034>