AsyncSemaphore.toString method added

redisson/src/main/java/org/redisson/pubsub/AsyncSemaphore.java

@@ -120,4 +120,11 @@ public class AsyncSemaphore {
         }
     }
 
+    @Override
+    public String toString() {
+        return "AsyncSemaphore [counter=" + counter + "]";
+    }
+    
+    
+    
 }