text: import { observable, action } from 'mobx';
  
  //
  // MobX store class
  //
  export default class AppStore {
    // state
    @observable counter = 10;
  
    // actions
    @action.bound
    increment() {
      this.counter += 1;
    }
  
    @action.bound
    decrement() {
      this.counter -= 1;
    }
  }
  