diff --git a/src/main/java/org/gcube/accounting/insert/rstudio/persistence/AggregatorPersistenceBackendQueryConfiguration.java b/src/main/java/org/gcube/accounting/insert/rstudio/persistence/AggregatorPersistenceBackendQueryConfiguration.java
index 810ffaa..cce7bae 100644
--- a/src/main/java/org/gcube/accounting/insert/rstudio/persistence/AggregatorPersistenceBackendQueryConfiguration.java
+++ b/src/main/java/org/gcube/accounting/insert/rstudio/persistence/AggregatorPersistenceBackendQueryConfiguration.java
@@ -17,7 +17,7 @@ public class AggregatorPersistenceBackendQueryConfiguration extends AccountingPe
 	}
 	
 	/**
-	 * @param class1 The class of the persistence to instantiate
+	 * @param persistence The class of the persistence to instantiate
 	 * @throws Exception if fails
 	 */
 	@SuppressWarnings({ "unchecked", "rawtypes" })
diff --git a/src/main/java/org/gcube/accounting/insert/rstudio/plugin/Utility.java b/src/main/java/org/gcube/accounting/insert/rstudio/plugin/Utility.java
index 7c8c99c..7cc42ed 100644
--- a/src/main/java/org/gcube/accounting/insert/rstudio/plugin/Utility.java
+++ b/src/main/java/org/gcube/accounting/insert/rstudio/plugin/Utility.java
@@ -12,7 +12,7 @@ public class Utility {
 	/**
 	 * Generate a key for map-reduce
 	 * @param key
-	 * @return
+	 * @return JsonArray
 	 */
 	protected static JsonArray generateKey(String scope,String key){		
 		JsonArray generateKey = JsonArray.create();
@@ -26,10 +26,11 @@ public class Utility {
 		return generateKey;
 
 	}
+	
 	/**
 	 * Verify a  record aggregated for insert into bucket
 	 * @param item
-	 * @return
+	 * @return boolean
 	 */
 	public static boolean checkType(Object item) {
 		return item == null