meminfo_objects_summary() undefined

Hi! I'm trying to fix some script using this extension and referenced presentation. There is meminfo_objects_summary() function used on one of slides, but it seems there is no such function on my installation:

$ php -v
PHP 5.6.20 (cli) (built: Mar 31 2016 07:24:47) 
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
    with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies
    with Xdebug v2.3.3, Copyright (c) 2002-2015, by Derick Rethans

$ php -i | grep meminfo
/etc/php.d/meminfo.ini
meminfo

$ php -r '$funcs = get_defined_functions()["internal"]; $filtered = array_filter($funcs, function($name){return false !== strpos($name, "meminfo");}); var_dump($filtered);'
array(1) {
  [1963]=>
  string(12) "meminfo_dump"
}

What I'm doing wrong?

BitOne / php-meminfo

meminfo_objects_summary() undefined #65