public static CoordinatorMessageKey deserializeCoordinatorMessageKeyFromJson(String coordinatorMsgKeyAsJson) {
    try {
      return OBJECT_MAPPER.readValue(coordinatorMsgKeyAsJson, CoordinatorMessageKey.class);
    } catch (IOException e) {
      throw new SamzaException(String.format("Exception occurred when deserializing the coordinatorMsgKey: %s", coordinatorMsgKeyAsJson), e);
    }
  }
Deserializes the @param coordinatorMsgKeyAsString in json format to {@link CoordinatorMessageKey}.
@param coordinatorMsgKeyAsJson the serialized CoordinatorMessageKey in json format.
@return the deserialized CoordinatorMessageKey.
samza-core/src/main/java/org/apache/samza/coordinator/metadatastore/CoordinatorStreamStore.java