code: function getResponsiveState(state) {
      if (state === null || state == undefined) {
          throw new Error('[Pastate] Can not get responsive state from null or undefined');
      }
      if (!state.__store__) {
          throw new Error('[Pastate] You can only get responsive state from pastate immutable state');
      }
      return state.__store__.getResponsiveState(state);
  }
docs: /* --- store 内部函数调用门面 --- 
  把 imState 转化为响应式 state