@Override
  public Map<String, String> toConfig(Config jobConfig) {
    Map<String, String> tableConfig = new HashMap<>(super.toConfig(jobConfig));
    // Store factory configuration
    tableConfig.put(String.format(StorageConfig.FACTORY, tableId),
        InMemoryKeyValueStorageEngineFactory.class.getName());
    return Collections.unmodifiableMap(tableConfig);
  }
Constructs a table descriptor instance
@param tableId Id of the table, it must conform to pattern {@literal [\\d\\w-_]+}
@param serde the serde for key and value
samza-kv-inmemory/src/main/java/org/apache/samza/storage/kv/inmemory/descriptors/InMemoryTableDescriptor.java