### Question:
BloomFilterManagerImpl implements BloomFilterManager<T, C>,
        Listenable<BloomFilterManagerListener<? super T, C>> { @Override public T ensureGetValidFilter(String name) throws FilterNotFoundException { final T filter = getFilter(name); if (filter == null || !filter.valid()) { throw FILTER_NOT_FOUND_EXCEPTION; } return filter; } BloomFilterManagerImpl(BloomFilterFactory<? extends T, ? super C> factory); @Override CreateFilterResult<T> createFilter(String name, C config, boolean overwrite); @Override void addFilters(Iterable<FilterRecord<? extends T>> filters); @Nullable @Override T getFilter(String name); @Override T ensureGetValidFilter(String name); @Override List<String> getAllFilterNames(); @Override int size(); @Override void remove(String name); @Override void remove(String name, T filter); @Override Iterator<FilterRecord<T>> iterator(); @Override void addListener(BloomFilterManagerListener<? super T, C> listener); @Override boolean removeListener(BloomFilterManagerListener<? super T, C> listener);  }### Answer:
@Test public void testSafeGetNonExistsFilter() { assertThatThrownBy(() -> manager.ensureGetValidFilter(testingFilterName)) .isInstanceOf(FilterNotFoundException.class); }