private def equalsArrayDataLink(a1: FArrayDataLink, a2: FArrayDataLink): Boolean = {
    if (a1.uuids.size != a2.uuids.size) {
      false
    } else {
      var equals = true
      a2.uuids.foreach(id =>
        if (!a1.uuids.toSet.contains(id)) {
          equals = false
        }
      )
      equals
    }
  }

  private def columnValues(column: Column, entities: Iterable[Entity]): Map[Type, Iterable[UUID]] = {
    val result = scala.collection.mutable.Map[Type, ListBuffer[UUID]]()
    val links = scala.collection.mutable.Map[String, Type]()
    entities.foreach{
      case (entity) =>
        val value = entity.properties.find(_._1 == column).orNull
        if (value != null) {
          var key = value._2

          value._2 match {
            case links: FArrayDataLink =>
              val link = result.keys.filter(_.isInstanceOf[FArrayDataLink]).find(v => equalsArrayDataLink(v.asInstanceOf[FArrayDataLink], links)).orNull
              if (link == null) {
                result.put(key, new ListBuffer[UUID]())
              } else {
                key = link
              }
            case _ =>
              if (!result.keys.exists(_ == key)) {
                result.put(key, new ListBuffer[UUID]())
              }
          }

          result(key) += entity.key
        }
    }
    result.toMap
  }