public IEnumerable <Resource> GetDisabledResourceAncestors(IEnumerable <Resource> availableResources)
{
var missingParentIds = availableResources
.Where(x => x.ParentResourceId.HasValue)
.SelectMany(x => resourceAncestors[x.Id]).Distinct()
.Where(x => !availableResources.Select(y => y.Id).Contains(x));
return(resources.OfType <SlaveGroup>().Union(disabledParentResources).Where(x => missingParentIds.Contains(x.Id)));
}
