@Documented @Retention(value=RUNTIME) @Target(value=METHOD) public static @interface DoFn.StartBundle
DoFn.StartBundleContext, then it will be passed a context object for the current execution.
PipelineOptions, then it will be passed the options for the current pipeline.
DoFn.BundleFinalizer, then it will be passed a mechanism to register a callback that will be invoked after the runner successfully commits the output of this bundle. See Apache Beam Portability API: How to Finalize Bundles for further details.