'Looks up a single key in memcache.
If you have multiple items to load, though, it\'s much more efficient
to use get_multi() instead, which loads them in one bulk operation,
reducing the networking latency that\'d otherwise be required to do
many serialized get() operations.
Args:
key: The key in memcache to look up.  See docs on Client
for details of format.
namespace: a string specifying an optional namespace to use in
the request.
for_cas: If True, request and store CAS ids on the client (see
cas() operation below).
Returns:
The value of the key, if found in memcache, else None.'

def get(self, key, namespace=None, for_cas=False):

    if _is_pair(key):
        key = key[1]
    rpc = self.get_multi_async([key], namespace=namespace, for_cas=for_cas)
    results = rpc.get_result()
    return results.get(key)
