@Override
  public List<? extends TableDescriptor<K, V, ?>> getTableDescriptors() {
    return cache != null
        ? Arrays.asList(cache, table)
        : Arrays.asList(table);
  }
Retrieve user-defined table descriptors contained in this table
@return table descriptors
samza-api/src/main/java/org/apache/samza/table/descriptors/CachingTableDescriptor.java