public function test_remove_anonymous_callback() {
    $tag = __FUNCTION__;
    $a   = new MockAction();
    add_action( $tag, array( $a, 'action' ), 12, 1 );
    $this->assertTrue( has_action( $tag ) );

    $hook = $GLOBALS['wp_filter'][ $tag ];

    // From http://wordpress.stackexchange.com/a/57088/6445
    foreach ( $hook as $priority => $filter ) {
      foreach ( $filter as $identifier => $function ) {
        if ( is_array( $function )
          && is_a( $function['function'][0], 'MockAction' )
          && 'action' === $function['function'][1]
        ) {
          remove_filter(
            $tag,
            array( $function['function'][0], 'action' ),
            $priority
          );
        }
      }
    }

    $this->assertFalse( has_action( $tag ) );
  }