1 files changed, 6 insertions, 0 deletions
diff --git a/Lib/xml/etree/ElementTree.py b/Lib/xml/etree/ElementTree.py
index 10bf849..3981659 100644
--- a/Lib/xml/etree/ElementTree.py
+++ b/Lib/xml/etree/ElementTree.py
@@ -1190,9 +1190,15 @@ def tostringlist(element, encoding=None, method=None):
         def writable(self):
             return True
 
+        def seekable(self):
+            return True
+
         def write(self, b):
             data.append(b)
 
+        def tell(self):
+            return len(data)
+
     ElementTree(element).write(DataStream(), encoding, method=method)
     return data