php7 get_class() warning

[devprofession]

On php 7.2 there is a warning:
Warning: get_class() expects parameter 1 to be object, null given

get_class ([ object $object ] ) : string
Php 7.2.0 | NULL was removed as the default value for object, and is no longer a valid input.
http://php.net/manual/en/function.get-class.php