Added the FieldValidationError reference to the references module

lodel/leapi/datahandlers/base_classes.py

@@ -10,6 +10,7 @@ import inspect
 
 from lodel import logger
 
+
 class FieldValidationError(Exception):
     pass
 

lodel/leapi/datahandlers/references.py

@@ -1,7 +1,10 @@
 # -*- coding: utf-8 -*-
-from lodel.leapi.datahandlers.base_classes import Reference, MultipleRef, SingleRef
+from lodel.leapi.datahandlers.base_classes import Reference, MultipleRef, SingleRef, FieldValidationError
+
+
+class Link(SingleRef):
+    pass
 
-class Link(SingleRef): pass
 
 ##@brief Child class of MultipleRef where references are represented in the form of a python list
 class List(MultipleRef):