return value of proxy functions

[cutewalker]

for the proxy functions as following

• Cache.set
• Cache.add
• Cache.delete
• Cache.delete_many
• Cache.clear
• Cache.set_many

the return value is always None.
but we sometimes really need the return value of the internal cache object 's operations.
for example, we can use memcache.add as a distributed lock to guarantee atomic operations:

if memcache.add(key, value):
    do_something_exclusively
else:
    # someone else is doing the same thing
    pass

but without the retuen value, we have to use cache.cache.add.

So, would you consider this and change the proxy functions like this:

     def add(self, *args, **kwargs):
         "Proxy function for internal cache object."
-        self.cache.add(*args, **kwargs)
+        return self.cache.add(*args, **kwargs)

or is there some other reason to keep discarding interal operation's return value ?