Description:
------------
---
From manual page: https://php.net/class.dateinterval
---

There are now more public properties, but none of these new ones have been documented yet.

Please add these new properties and explain how to use them.

Expected result:
----------------
/* Properties */
public integer $y ;
public integer $m ;
public integer $d ;
public integer $h ;
public integer $i ;
public integer $s ;
public float $f ;
public integer $weekday ;
public integer $weekday_behavior ;
public integer $first_last_day_of ;
public integer $invert ;
public mixed $days ;
public integer $special_type ;
public integer $special_amount ;
public integer $have_weekday_relative ;
public integer $have_special_relative ;


Actual result:
--------------
/* Properties */
public integer $y ;
public integer $m ;
public integer $d ;
public integer $h ;
public integer $i ;
public integer $s ;
public float $f ;
public integer $invert ;
public mixed $days ;