Index: tests/conftest.py
===================================================================
--- tests/conftest.py	(revision d7499cad8c700086cf682c7c11caf3a253c4fcc6)
+++ tests/conftest.py	(revision e458b5a04c0ef82f3ff6446cbd483b09b52f3c67)
@@ -59,11 +59,9 @@
         return cls()
 
-    def to_dict(self):
-        base = super().to_dict()
-        base.update({
+    def _serialize_content(self):
+        return {
             "text": self.text,
             "options": [opt.to_dict() for opt in self.options],
-        })
-        return base
+        }
 
     @property