### Question:
NestedPersistentStateManager implements PersistentStateManager, PersistentStateInterface { @Override public void close() { }  @Override Map<String, Object> copyPersistentState(); @Override void initWithPersistentState(@Nullable Map<String, Object> persistentState); @Override void setPersistentStateListener(@Nullable PersistentStateListener listener); @Override synchronized void startManaging(
            String objectName, PersistentStateInterface objectInstance); @Override synchronized void stopManaging(String objectName); @Override void refresh(String objectName); @Override void refresh(); @Override void reset(String objectName); @Override void reset(); @Override void flush(); @Override void close();  }### Answer:
@Test void close() throws IOException, CorruptPersistentStateException { Map<String, Object> state = new HashMap<>(); NestedPersistentStateManager persistentStateManager = new NestedPersistentStateManager(); persistentStateManager.initWithPersistentState(state); state = persistentStateManager.copyPersistentState(); persistentStateManager.close(); }