diff --git a/org.springframework.integration/src/main/java/org/springframework/integration/aggregator/MessageGroup.java b/org.springframework.integration/src/main/java/org/springframework/integration/aggregator/MessageGroup.java
index 41aca1d3fe..28d6123a45 100644
--- a/org.springframework.integration/src/main/java/org/springframework/integration/aggregator/MessageGroup.java
+++ b/org.springframework.integration/src/main/java/org/springframework/integration/aggregator/MessageGroup.java
@@ -5,7 +5,8 @@ import org.springframework.integration.core.Message;
 import java.util.*;
 
 /**
- * Represents an mutable group of correlated messages that is bound to a certain {@link org.springframework.integration.store.MessageStore}
+ * Represents an mutable group of correlated messages that is bound to a certain
+ * {@link org.springframework.integration.store.MessageStore}
  * and correlation key. The group will grow during its lifetime, when messages are <code>add</code>ed to it. <strong>
  * This is not thread safe and should not be used for long running aggregations</strong>.
  * <p/>
@@ -16,7 +17,6 @@ import java.util.*;
  * group is completed.
  *
  *
- *
  * @author Iwein Fuld
  * @author Oleg Zhurakousky
  */
@@ -27,14 +27,19 @@ public class MessageGroup {
     private final List<MessageGroupListener> listeners;
 
 
-    public MessageGroup(Collection<? extends Message<?>> originalMessages, CompletionStrategy completionStrategy, Object correlationKey,
-                          MessageGroupListener... listeners) {
+    public MessageGroup(Collection<? extends Message<?>> originalMessages, CompletionStrategy completionStrategy,
+                        Object correlationKey, MessageGroupListener... listeners) {
         this.completionStrategy = completionStrategy;
         this.correlationKey = correlationKey;
         this.messages.addAll(originalMessages);
         this.listeners = Collections.unmodifiableList(Arrays.asList(listeners));
     }
 
+    /**
+     * This method determines whether messages have been added to this group that supersede the given message based on
+     * its sequence id. This can be helpful to avoid ending up with sequences larger than their required sequence size,
+     * or sequences that are missing certain sequence numbers.
+     */
     public boolean hasNoMessageSuperseding(Message<?> message) { 	
         Integer messageSequenceNumber = message.getHeaders().getSequenceNumber();
         if (messageSequenceNumber > 0){
@@ -43,7 +48,7 @@ public class MessageGroup {
             }
             for (Message<?> member : messages) {
                 Integer memberSequenceNumber = member.getHeaders().getSequenceNumber();
-                if (memberSequenceNumber == messageSequenceNumber) {
+                if (memberSequenceNumber.equals(messageSequenceNumber)) {
                     return false;
                 }
             }
@@ -51,28 +56,48 @@ public class MessageGroup {
         return true;
     }
 
-    public void add(Message<?> message) {
+    /**
+     * Add a message to the internal list. This is needed to avoid hitting the underlying store or copying the internal
+     * list. Use with care.
+     */
+    protected void add(Message<?> message) {
         messages.add(message);
     }
 
+    /**
+     * {@inheritDoc}
+     */
     public boolean isComplete() {
         return completionStrategy.isComplete(messages);
     }
 
+    /**
+     * @return internal message list, modification is allowed, but not recommended
+     */
     public List<Message<?>> getMessages() {
         return messages;
     }
 
+    /**
+     * @return the correlation key that links these messages together according to a particular CorrelationStrategy
+     */
     public Object getCorrelationKey() {
         return correlationKey;
     }
 
+    /**
+     * Call this method to sign off on processing of certain messages e.g. from a MessageProcessor. Typically this will
+     * remove these messages from the processing backlog.
+     */
     public void onProcessingOf(Message... messages) {
         for (MessageGroupListener listener : listeners) {
             listener.onProcessingOf(messages);
         }
     }
 
+    /**
+     * Call this method to signal the completion of the processing of an entire group
+     */
     public void onCompletion() {
         for (MessageGroupListener listener : listeners) {
             listener.onCompletionOf(correlationKey);