code: @SuppressWarnings("rawtypes")
      public Class<? extends TBase> getMessageClass(String topic) {
          return allTopics ? messageClassForAll : messageClassByTopic.get(topic);
      }
docs: Returns configured thrift message class for the given Kafka topic
  
  @param topic
  Kafka topic
  @return thrift message class used by this utility instance, or
  <code>null</code> in case valid class couldn't be found in the
  configuration.