[KARAF-4874] Add comparable on the cluster log key
diff --git a/log/src/main/java/org/apache/karaf/cellar/log/ClusterLogKey.java b/log/src/main/java/org/apache/karaf/cellar/log/ClusterLogKey.java
index 662d095..dde698e 100644
--- a/log/src/main/java/org/apache/karaf/cellar/log/ClusterLogKey.java
+++ b/log/src/main/java/org/apache/karaf/cellar/log/ClusterLogKey.java
@@ -18,7 +18,7 @@
 
 import java.io.Serializable;
 
-public class ClusterLogKey implements Serializable {
+public class ClusterLogKey implements Serializable, Comparable<ClusterLogKey> {
 
     private String nodeId;
     private String nodeAlias;
@@ -57,4 +57,9 @@
         this.id = id;
     }
 
+    @Override
+    public int compareTo(ClusterLogKey o) {
+        return new Long(this.timeStamp - o.timeStamp).intValue();
+    }
+
 }