public IEnumerable <IStateNode> GetChilds()
{
return(_root.TargetServer.RunningVMs
.Where(vm => !vm.IsMigrating)
.Where(vm => Changes.All(record => record.Target.Id != vm.Id))
.OrderByDescending((vm) => vm.Resources.GetValue())
.Take(MigrationParams.Current.MaxMigrateCandidatesPerStep) // GlobalConstants.VM_PER_SERVER
.SelectMany((vm) => CreateChildNodes(vm)));
}