Sonar fixes

Rule: Use isEmpty() to check whether the collection is empty or not.

Change-Id: Ib5ab56b2263623b297db56c5cac2c2ee80e12725
diff --git a/providers/openflow/meter/src/main/java/org/onosproject/provider/of/meter/impl/MeterModBuilder.java b/providers/openflow/meter/src/main/java/org/onosproject/provider/of/meter/impl/MeterModBuilder.java
index 5d2a101..406337b 100644
--- a/providers/openflow/meter/src/main/java/org/onosproject/provider/of/meter/impl/MeterModBuilder.java
+++ b/providers/openflow/meter/src/main/java/org/onosproject/provider/of/meter/impl/MeterModBuilder.java
@@ -155,6 +155,6 @@
     private void validate() {
         checkNotNull(id, "id cannot be null");
         checkNotNull(bands, "Must have bands");
-        checkArgument(bands.size() > 0, "Must have at lease one band");
+        checkArgument(!bands.isEmpty(), "Must have at lease one band");
     }
 }