diff --git a/src/linkahead/common/models.py b/src/linkahead/common/models.py
index 6f37c217a335e034cc06cc89e0ede1fa7765d53a..6cafad9cbee216b919eabcfbacc286e69545c47c 100644
--- a/src/linkahead/common/models.py
+++ b/src/linkahead/common/models.py
@@ -1232,7 +1232,7 @@ class Entity:
         xml: Optional[etree._Element] = None,
         add_properties: INHERITANCE = "ALL",
         local_serialization: bool = False,
-        visited_entities: Optional[Union[list, None]] = None
+        visited_entities: Optional[list] = None
     ) -> etree._Element:
         """Generate an xml representation of this entity. If the parameter xml
         is given, all attributes, parents, properties, and messages of this
@@ -1240,15 +1240,25 @@ class Entity:
 
         Raise an error if xml is not a lxml.etree.Element
 
-        @param xml: an xml element to which all attributes, parents,
-            properties, and messages
-            are to be added.
-        @param visited_entities: recursion check, should never be set manually
-
-        FIXME: Add documentation for the add_properties parameter.
-        FIXME: Add documentation for the local_serialization parameter.
+        Parameters
+        ----------
+        xml : etree._Element, optional
+            an xml element to which all attributes, parents,
+            properties, and messages are to be added. Default is None.
+        visited_entities : list, optional
+            list of enties that are being printed for recursion check,
+            should never be set manually. Default is None.
+        add_properties : INHERITANCE, optional
+            FIXME: Add documentation for the add_properties
+            parameter. Default is "ALL".
+        local_serialization : bool, optional
+            FIXME: Add documentation for the local_serialization
+            parameter. Default is False.
 
-        @return: xml representation of this entity.
+        Returns
+        -------
+        xml : etree._Element
+            xml representation of this entity.
         """
 
         if xml is None:
@@ -1282,8 +1292,10 @@ class Entity:
             xml.set("description", str(self.description))
 
         if self.version is not None:
-            # Does version.to_xml need visited_entities support?
-            # It does have some recursion with predecessors / successors.
+            # If this ever causes problems, we might add
+            # visited_entities support here since it does have some
+            # recursion with predecessors / successors. But should be
+            # fine for now, since it is always set by the server.
             xml.append(self.version.to_xml())
 
         if self.value is not None: