fix: address comments

Author: aMahanna

arango/collection.py

@@ -1992,15 +1992,16 @@ def import_bulk(
             IMPORTANT NOTE: this parameter may go through breaking changes
             in the future where the return type may not be a list of result
             objects anymore. Use it at your own risk, and avoid
-            depending on the return value if possible. Should not be used
-            if **overwrite** is set to true.
+            depending on the return value if possible. Cannot be used with
+            parameter **overwrite**.
         :type batch_size: int
         :return: Result of the bulk import.
         :rtype: dict | list[dict]
         :raise arango.exceptions.DocumentInsertError: If import fails.
         """
-        if overwrite and batch_size:
-            raise ValueError("Cannot set **batch_size** if **overwrite** is true")
+        if overwrite and batch_size is not None:
+            msg = "Cannot use parameter 'batch_size' if 'overwrite' is set to True"
+            raise ValueError(msg)
 
         documents = [self._ensure_key_from_id(doc) for doc in documents]