typo

src/mongopersist/zope/container.py

@@ -236,7 +236,7 @@ def __setitem__(self, key, value):
         contained.setitem(self, self._real_setitem, key, value)
 
     def add(self, value, key=None):
-        # We are already suporting ``None`` valued keys, which prompts the key
+        # We are already supporting ``None`` valued keys, which prompts the key
         # to be the OID. But people felt that a more explicit interface would
         # be better in this case.
         self[key] = value