public function test_wp_add_dashboard_widget() {
    global $wp_meta_boxes;

    set_current_screen( 'dashboard' );

    if ( ! function_exists( 'wp_add_dashboard_widget' ) ) {
      require_once ABSPATH . 'wp-admin/includes/dashboard.php';
    }

    // Some hardcoded defaults for core widgets.
    wp_add_dashboard_widget( 'dashboard_quick_press', 'Quick', '__return_false' );
    wp_add_dashboard_widget( 'dashboard_browser_nag', 'Nag', '__return_false' );

    $this->assertArrayHasKey( 'dashboard_quick_press', $wp_meta_boxes['dashboard']['side']['core'] );
    $this->assertArrayHasKey( 'dashboard_browser_nag', $wp_meta_boxes['dashboard']['normal']['high'] );

    // Location and priority defaults.
    wp_add_dashboard_widget( 'dashboard1', 'Widget 1', '__return_false', null, null, 'foo' );
    wp_add_dashboard_widget( 'dashboard2', 'Widget 2', '__return_false', null, null, null, 'bar' );

    $this->assertArrayHasKey( 'dashboard1', $wp_meta_boxes['dashboard']['foo']['core'] );
    $this->assertArrayHasKey( 'dashboard2', $wp_meta_boxes['dashboard']['normal']['bar'] );

    // Cleanup.
    remove_meta_box( 'dashboard_quick_press', 'dashboard', 'side' );
    remove_meta_box( 'dashboard_browser_nag', 'dashboard', 'normal' );
    remove_meta_box( 'dashboard1', 'dashboard', 'foo' );

    // This doesn't actually get removed due to the invalid priority.
    remove_meta_box( 'dashboard2', 'dashboard', 'normal' );
  }