<?php
is_a($x, $y);
is_a($x, 'SomeClass');
is_a($x, '\\SomeClass');
is_a($x, '\\'.'Some'.'Class');
~~~~~~~~~~
advice:2:1
advice:3:1
advice:4:1
advice:5:1
~~~~~~~~~~
<?php
$x instanceof $y;
$x instanceof SomeClass;
$x instanceof \SomeClass;
is_a($x, '\\'.'Some'.'Class');
