class_uses does not work on subclasses

class_uses.php

 
 Trait SomeTrait
 {
 }
 
 
 class A
 {
     use SomeTrait;
 }
 
 
 class B extends A
 {
 }
 
 var_dump(class_uses(new A));
 var_dump(class_uses(new B));




// The output is:
array(1) {
  ["SomeTrait"]=>
  string(9) "SomeTrait"
}
array(0) {
}

DIrectly from the php documentation:

This function returns an array with the names of the traits that the given class uses. This does however not include any traits used by a parent class.