code: def load_states(self, fname):
          
          if not self._kv_initialized:
              self._init_kvstore()
          if self._params_to_init:
              self._init_params()
  
          if self._update_on_kvstore:
              self._kvstore.load_optimizer_states(fname)
              self._optimizer = self._kvstore._updater.optimizer
          else:
              with open(fname, 'rb') as f:
                  states = f.read()
              for updater in self._updaters:
                  updater.set_states(states)
                  updater.optimizer = self._updaters[0].optimizer
              self._optimizer = self._updaters[0].optimizer
          param_dict = {i: param for i, param in enumerate(self._params)}
          self._optimizer.param_dict = param_dict
docs: Loads trainer states (e.g. optimizer, momentum) from a file.
  
          Parameters
          ----------
          fname : str
              Path to input states file.
  
          Note
          ----
          `optimizer.param_dict`, which contains Parameter information (such as
          `lr_mult` and `wd_mult`) will not be loaded from the file, but rather set
          based on current Trainer's parameters.