public function test_new_theme_previously_active() {
    $this->register_nav_menu_locations( array( 'primary' ) );

    $prev_theme_nav_menu_locations = array(
      'primary'   => 1,
      'secondary' => 2,
    );

    // Nav menu location assignments that were set on the next theme when it was previously active.
    $old_next_theme_nav_menu_locations = array(
      'primary' => 3,
    );

    $new_next_theme_nav_menu_locations = wp_map_nav_menu_locations( $old_next_theme_nav_menu_locations, $prev_theme_nav_menu_locations );

    $expected_nav_menu_locations = wp_array_slice_assoc( $prev_theme_nav_menu_locations, array_keys( get_registered_nav_menus() ) );
    $this->assertSame( $expected_nav_menu_locations, $new_next_theme_nav_menu_locations );
  }