addEntity(name, desc) {
            let id = this.newEntityIndex++;
            this.entities.set(id, new EntityInfo(id, name, desc));
            return id;
        }
/**
         *
         * @param name name of the entity
         * @param desc a helpful debugging description
         */
@param name name of the entity
@param desc a helpful debugging description
@param name name of the entity @param desc a helpful debugging description
addEntity(name, desc) {
            let id = this.newEntityIndex++;
            this.entities.set(id, new EntityInfo(id, name, desc));
            return id;
        }
addEntity ( name , desc ) { let id = this . newEntityIndex ++ ; this . entities . set ( id , new EntityInfo ( id , name , desc ) ) ; return id ; }
@param name name of the entity
 @param desc a helpful debugging description
@param name name of the entity @param desc a helpful debugging description