getRelativesAsResources method
Returns a list of Resource objects that represent the relatives of
this Resource.
Throws MissingHueNetworkException if the hueNetwork is null, if a
Relative cannot be found on the hueNetwork, or if the relative's
ResourceType cannot be found on the hueNetwork.
Implementation
List<Resource> getRelativesAsResources(List<Relative> relatives) {
  List<Resource> toReturn = [];
  for (Relative relative in relatives) {
    toReturn.add(getRelativeAsResource(relative));
  }
  return toReturn;
}