Resolved : After 2.6 upgrade , smart Search Suggestions crashed

After my Litecart was upgraded to 2.6 from 2.5.5 version , smart Search Suggestions was not Working . And in the Vmods , Eyecandy Product Search 's health was showing Failed
In that Vmods, General tab , under modifications heading ,

includes/library/lib_document.inc.php tab was showing in red color color ,

inside that tab, under operations header, Find field , it was written as

self::$snippets['head_tags']['fontawesome'] = '<link rel="stylesheet" href="'. document::href_rlink(FS_DIR_APP .'ext/fontawesome/font-awesome.min.css') .'">';

in this line , when the word document:: is replaced with self:: , this starts working , and health status changed to OK and smart search suggestions working fine

Hope this won't create any other issues ..