code: @CheckReturnValue
    public static Builder fromPool(Pool pool) {
      return new BuilderImpl(pool.poolShutdown, () -> {
        try {
          return pool.dataSource.getConnection();
        } catch (Exception e) {
          throw new DatabaseException("Unable to obtain a connection from the DataSource", e);
        }
      }, new OptionsDefault(pool.flavor));
    }
docs: Use an externally configured DataSource, Flavor, and optionally a shutdown hook.
  The shutdown hook may be null if you don't want calls to Builder.close() to attempt
  any shutdown. The DataSource and Flavor are mandatory.