code: function cacheKey () {
      //  get cache id
      var cacheId = stableId({
          args: this.query.args,
          columnsId: this.cache.model.columnsId,
      })
      // create cache key
      return `${this.cache.model.name}:view:select:collection:${cacheId}`
  }
docs: @function cacheKey
  
  @returns {string}