@Override
  public void deleteAll(List<K> keys) {
    for (K k : keys) {
      delete(k);
    }
  }
An in-memory store that supports range queries.

@param <K> the type of keys in the store
@param <V> the type of values in the store
samza-core/src/test/java/org/apache/samza/operators/impl/store/TestInMemoryStore.java