#569 adding return values to NodeElement so action method chaining be p...

In continue to #569 suggestion, here is PR
`this` isn't a valid return type. The valid return types in this case is:

* self - would always auto-complete from NodeElement class
* static - would auto-complete from actual instantiated class, but not sure if anybody except PhpStorm supports it.

I prefer `static` as return type here.