local in-processs tf.data service workers. `"AUTO"` works well for most
        cases, while users can specify other targets. For example, `"LOCAL"`
        would help avoid RPCs and data copy if every TF worker colocates with a
        tf.data service worker. Currently, `"AUTO"` reads from any tf.data
        service workers to preserve existing behavior. The default value is
        `"AUTO"`.