code: def load_state(self, key, delete=True):
          
          with self.load_stream(key, binary=True) as f:
              state = self._serializer.deserialize(f)
              if delete:
                  self.rm(key)
              return state
docs: Load a state from storage.
  
          :param key: key that identifies state
          :rtype: manticore.core.StateBase