docs: @Bean
    public DataSource dataSource() {
      DriverManagerDataSource dataSource = new DriverManagerDataSource(dbUrl, userName, password);
      dataSource.setDriverClassName(Driver.class.getName());
  
      // no need shutdown, EmbeddedDatabaseFactoryBean will take care of this
      // EmbeddedDatabaseBuilder builder = new EmbeddedDatabaseBuilder();
      // EmbeddedDatabase dataSource = builder.setType(EmbeddedDatabaseType.H2).setName("h2_example").build();
      return dataSource;
    }