What will be the output of the following PHP code?

What will be the output of the following PHP code?

interface A { public function foo(); }
interface B { public function bar(); }
class Test implements A, B {
  public function foo() { return 'foo'; }
  public function bar() { return 'bar'; }
}
$obj = new Test();
echo $obj->foo() . ' ' . $obj->bar();