text: import EventEmitter from 'events';
  
  class ObservableMixin extends EventEmitter {
  
      /**
       * Format: {UPDATE: 'update', ADD: 'add'}
       */
      static getEvents() {
          throw new Error('At least one event must be defined in observable class');
      }
  
      constructor() {
          super(...arguments);
          this.__muted = false;
      }
  
      mute() {
          this.__muted = true;
      }
  
      unMute() {
          this.__muted = false;
      }
  }
  
  export default ObservableMixin;