message: added entity to column
diff: @@ -825,6 +825,16 @@ export class Column<dataType> {
  }
  }
  + private _entity: Entity<any>;
  + __setEntity(e: Entity<any>) {
  + this._entity = e;
  + }
  + get entity() { return this._entity.lookup; }
  + lookup<lookupIdType, entityType extends Entity<lookupIdType>>(lookupEntity: entityType, filter?: Column<lookupIdType> | ((entityType: entityType) => FilterBase)): entityType {
  + if (!filter)
  + filter = <any> this ;
  + return this._entity.lookup(lookupEntity, filter);
  + }
  __isVirtual() {
  if (this.__settings && this.__settings.virtualData)
  return true;
  @@ -1242,6 +1252,7 @@ export class Entity<idType> {
  y.__valueProvider = this.__entityData;
  if (this.__columns.indexOf(y) < 0)
  this.__columns.push(y);
  + y.__setEntity(this);
  }
  private __columns: Column<any>[] = [];
  __getColumn<T>(col: Column<T>) {
  