add class info of pollGenericMessages

Author: dbl-x

openmessaging-api-samples/src/main/java/io/openmessaging/samples/consumer/GenericPullConsumerApp.java

@@ -57,7 +57,7 @@ public void run() {
         consumer.assign(topicPartitions);
         consumer.start();
 
-        List<GenericMessage<MessageSample>> messages = consumer.pollGenericMessages(1000);
+        List<GenericMessage<MessageSample>> messages = consumer.pollGenericMessages(1000, MessageSample.class);
         for (GenericMessage<MessageSample> message : messages) {
             System.out.println("Received message: " + message.getValue());
         }

openmessaging-api/src/main/java/io/openmessaging/api/PullConsumer.java

@@ -74,9 +74,10 @@ interface TopicPartitionChangeListener {
      * any topics or partitions before polling for data.
      *
      * @param timeout in millisecond
+     * @param tClass class of message body
      * @return
      */
-    <T> List<GenericMessage<T>> pollGenericMessages(long timeout);
+    <T> List<GenericMessage<T>> pollGenericMessages(long timeout, Class<T> tClass);
 
     /**
      * Overrides the fetch offsets that the consumer will use on the next {@link #poll(long)} }. If this API is invoked