@Documented
@Retention(value=RUNTIME)
@Target(value=PARAMETER)
public static @interface DoFn.Element
DoFn.ProcessElement, DoFn.GetInitialRestriction, DoFn.GetSize, DoFn.SplitRestriction, DoFn.GetInitialWatermarkEstimatorState, DoFn.NewWatermarkEstimator, and DoFn.NewTracker
methods.