text: 
  class GridEntityProxy {
      constructor() {
          this._entities = {}
      }
  
      registerGrid(id) {
          this._entities[id] = []
      }
  
      registerEntity(id, entity) {
          this._entities[id].push(entity)
      }
  
      query(gridIdList) {
          const entities = []
          for (let id of gridIdList) {
              entities.push(...this._entities[id])
          }
  
          return entities
      }
  }
  
  export default GridEntityProxy