```
@Documented
@Retention(RUNTIME)
@Target(METHOD)
public static @interface DoFn.StartBundle
```
Annotation for the method to use to prepare an instance for processing a batch of elements. The method annotated with this must satisfy the following constraints:
- If one of the parameters is of type DoFn.StartBundleContext, then it will be passed a context object for the current execution.
- If one of the parameters is of type PipelineOptions, then it will be passed the options for the current pipeline.
- If one of the parameters is of type 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.

Annotation Type DoFn.StartBundle