--- a/eric7/Graphics/UMLDiagramBuilder.py	Fri May 21 17:54:15 2021 +0200
+++ b/eric7/Graphics/UMLDiagramBuilder.py	Fri May 21 18:01:11 2021 +0200
@@ -65,15 +65,6 @@
         raise NotImplementedError(
             "Method 'buildDiagram' must be implemented in subclasses.")
     
-    def getPersistenceData(self):
-        """
-        Public method to get a string for data to be persisted.
-        
-        @return persisted data string
-        @rtype str
-        """
-        return ""
-    
     def parsePersistenceData(self, version, data):
         """
         Public method to parse persisted data.