code: private VarTupleSet getFailureTupleSet( RandSeq randSeq, FunctionInputDef inputDef)
      {
      List<Tuple> failureTuples = new ArrayList<Tuple>();
  
      for( VarDefIterator vars = new VarDefIterator( inputDef); vars.hasNext(); )
        {
        VarDef var = vars.next();
        for( Iterator<VarValueDef> failures = var.getFailureValues(); failures.hasNext(); )
          {
          failureTuples.add( new Tuple( new VarBindingDef( var, failures.next())));
          }
        }
      
      return new VarTupleSet( RandSeq.reorderIf( randSeq, failureTuples));
      }
docs: Returns the all failure input tuples required for generated test cases.