Revert "fixing issue CloudSlang#1118"

This reverts commit 0c8a95e.

content/io/cloudslang/base/lists/add_element.sl

@@ -21,26 +21,34 @@
 #!                 Example: '7'
 #! @input delimiter: The list delimiter
 #!
+#! @output response: 'success' or 'failure'
 #! @output return_result: The new list or an error message otherwise
+#! @output return_code: 0 if success, -1 if failure
 #!
 #! @result SUCCESS: The new list was retrieved with success
+#! @result FAILURE: Otherwise
 #!!#
 ########################################################################################################################
+
 namespace: io.cloudslang.base.lists
+
 operation:
   name: add_element
+
   inputs:
-    - list:
-        required: false
-    - element:
-        required: false
-    - delimiter:
-        default: ','
-        required: false
-  python_action:
-    script: |
-      list = list+delimiter+element if list else element
+    - list
+    - element
+    - delimiter
+
+  java_action:
+    gav: 'io.cloudslang.content:cs-lists:0.0.7'
+    class_name: io.cloudslang.content.actions.ListAppenderAction
+    method_name: appendElement
+
   outputs:
-    - return_result: ${list}
+    - return_result: ${returnResult}
+    - return_code: ${returnCode}
+
   results:
-    - SUCCESS
+    - SUCCESS: ${returnCode == '0'}
+    - FAILURE