Update src/visualization.py

src/visualization.py

@@ -203,9 +203,8 @@ def display_class_hierarchy_tree(ontology_manager, class_hierarchy):
                     st.markdown("*No subclasses*")
     
     # Display each root class
-        for root_class in sorted(root_classes):
-        for root_class in sorted(root_classes):
-            display_subclasses(root_class)
+    for root_class in sorted(root_classes):
+        display_subclasses(root_class)
 
 def get_class_depths(ontology_manager) -> Dict[str, int]:
     """Calculate the inheritance depth of each class."""