public IEnumerable <FeatureDescriptor> GetDependentFeatures(string featureId) { var dependants = _featureManager.GetDependentFeatures(featureId); var availableFeatures = _featureManager.GetAvailableFeatures().ToLookup(f => f.Id, StringComparer.OrdinalIgnoreCase); return(dependants .SelectMany(id => availableFeatures[id]) .ToList()); }