assertMessages example

$roles = [
      'anonymous1',
      'authenticated1',
      'administrator1',
      'migrate_test_role_11',
      'migrate_test_role_21',
      'migrate_test_role_3_that_is_longer_than_thirty_two_characters1',
    ];
    $this->assertEmpty(Role::loadMultiple($roles));

    $this->assertMessages($role_data, $id_map);
    $this->assertSame(4, $id_map->messageCount());

    // Remove the map row for the migrate_test_role_1 role and rerun the     // migration. This will re-import the migrate_test_role_1 role migration     // again.     $this->sourceDatabase->insert('role')
      ->fields([
        'rid' => 6,
        'name' => 'migrate test role 4',
      ])
      ->execute();