code: def get(self, key):
      '''Return the object named by key or None if it does not exist.
         CacheShimDatastore first checks its ``cache_datastore``.
      '''
      value = self.cache_datastore.get(key)
      return value if value is not None else self.child_datastore.get(keyf get(self, key):
      '''Return the object named by key or None if it does not exist.
         CacheShimDatastore first checks its ``cache_datastore``.
      '''
      value = self.cache_datastore.get(key)
      return value if value is not None else self.child_datastore.get(key)
docs: Return the object named by key or None if it does not exist.
         CacheShimDatastore first checks its ``cache_datastore``.