public function test_do_action_with_multiple_callbacks_on_different_priorities() {
    $a             = new MockAction();
    $b             = new MockAction();
    $callback_one  = array( $a, 'filter' );
    $callback_two  = array( $b, 'filter' );
    $hook          = new WP_Hook();
    $tag           = __FUNCTION__;
    $priority      = rand( 1, 100 );
    $accepted_args = rand( 1, 100 );
    $arg           = __FUNCTION__ . '_arg';

    $hook->add_filter( $tag, $callback_one, $priority, $accepted_args );
    $hook->add_filter( $tag, $callback_two, $priority + 1, $accepted_args );
    $hook->do_action( array( $arg ) );

    $this->assertSame( 1, $a->get_call_count() );
    $this->assertSame( 1, $a->get_call_count() );
  }