### Question:
LocalPartitionMapper extends Named implements Mapper, Delegated { @Override public Input create() { return Input.class.isInstance(input) ? Input.class.cast(input) : new InputImpl(rootName(), name(), plugin(), input); } protected  LocalPartitionMapper();  LocalPartitionMapper(final String rootName, final String name, final String plugin,
            final Serializable instance); @Override long assess(); @Override List<Mapper> split(final long desiredSize); @Override Input create(); @Override boolean isStream(); @Override void start(); @Override void stop(); @Override Object getDelegate();  }### Answer:
@Test void createReader() { final Mapper mapper = new LocalPartitionMapper("Root", "Test", "Plugin", new Component()); final Input input = mapper.create(); assertTrue(Record.class.isInstance(input.next())); assertNotSame(input.next(), input.next()); }
@Test void serialization() throws IOException, ClassNotFoundException { final LocalPartitionMapper mapper = Serializer.roundTrip(new LocalPartitionMapper("Root", "Test", "Plugin", new Component())); assertEquals("Root", mapper.rootName()); assertEquals("Test", mapper.name()); assertEquals("Plugin", mapper.plugin()); final Input input = mapper.create(); assertNotNull(input); }