diff --git a/src/caoscrawler/sync_graph.py b/src/caoscrawler/sync_graph.py
index 7589b556c3c70cf4124aec79cb41db3212a9c364..71b1f7eb8b654245a3794395ebfbf69a67270deb 100644
--- a/src/caoscrawler/sync_graph.py
+++ b/src/caoscrawler/sync_graph.py
@@ -290,12 +290,14 @@ class SyncGraph():
         Equivalent means that ID, path or identifiable are the same.
         If a new information was added to the given SyncNode (e.g. the ID), it might be possible
         then to identify an equivalent node (i.e. one with the same ID in this example).
-        There might be more than one equivalent nodes in the graph. However, simply the first that
-        is found is being returned. (When an equivalent node is found this, the given node is
+        There might be more than one equivalent node in the graph. However, simply the first that
+        is found is being returned. (When an equivalent node is found, the given node is
         typically merged, into the one that was found and after the merge the graph is again
-        checked for equivalent nodes)
+        checked for equivalent nodes.)
 
         Returns None if no equivalent node is found.
+
+        Last review by Alexander Schlemmer on 2024-05-28.
         """
         if entity.id is not None and entity.id in self._id_look_up:
             candidate = self._id_look_up[entity.id]
@@ -323,9 +325,13 @@ class SyncGraph():
     def _set_identifiable_of_node(self, node: SyncNode,
                                   identifiable: Optional[Identifiable] = None):
         """sets the identifiable and checks whether an equivalent node can be found with that new
-        information.
+        information. If an equivalent node is found, 'node' is merged into that node.
 
         if no identifiable is given, the identifiable is retrieved from the identifiable adapter
+
+        Raises a ValueError if the equivalent node found does not have an identifiable.
+        Raises a RuntimeError if there is no equivalent node found and
+          the (unique) string representation of the identifiable of node is already contained in the identifiable_look_up.
         """
         if identifiable is None:
             self.identifiableAdapter.all_identifying_properties_exist(node)