* MOVE logic for parsing filternames from the "unique string" in method
   FilteredBridgeSplitter.addRing() to new method
   FilteredBridgeSplitter.extractFilterNames().
 * ADD a FilteredBridgeSplitter.distributorName attribute which is set
   when Dist.Distributor.setDistributorName() is called.
 * REFACTOR FilteredBridgeSplitter.addRing() to use the new subring names.