### Question:
QueueMapper implements Mapper, JobStateAware, Supplier<DIPipeline>, Delegated { @Override public List<Mapper> split(final long desiredSize) { return singletonList(this); } QueueMapper(final String plugin, final String family, final String name,
            final PTransform<PBegin, PCollection<Record>> transform); String getStateId(); @Override long assess(); @Override List<Mapper> split(final long desiredSize); @Override Input create(); @Override boolean isStream(); @Override String plugin(); @Override String rootName(); @Override String name(); @Override void start(); @Override void stop(); @Override void setState(final State state); @Override DIPipeline get(); @Override Object getDelegate();  }### Answer:
@Test void split() { final QueueMapper mapper = new QueueMapper("test", "test", "test", null); try { mapper.setState(new JobStateAware.State()); } catch (final NullPointerException npe) { } final List<Mapper> split = mapper.split(mapper.assess()); assertEquals(1, split.size()); assertEquals(mapper, split.iterator().next()); }