code: public Collection<Tuple> getTuples( FunctionInputDef inputDef)
      {
      List<VarDef> combinedVars = getCombinedVars( inputDef);
      return getCombinedTuples( combinedVars, getTuples( combinedVars, getTupleSize()));
      }
docs: Returns all valid N-tuples of values for the included input variables.