docs: private static String containsDuplicates(List<BindingTuple> tuples) {
  		Set<String> sigs = new HashSet<String>();
  		for (BindingTuple tuple : tuples) {
  			if (!sigs.add(printSig(tuple.parameterized))) return printSig(tuple.parameterized);
  		}
  		
  		return null;
  	}