public static Optional<GeneratorSet> reduce( SystemInputDef inputDef)
    {
    return reduce( inputDef, GeneratorSet.basicGenerator(), null, new ReducerOptions());
    }
public static Optional < GeneratorSet > reduce ( SystemInputDef inputDef ) { return reduce ( inputDef , GeneratorSet . basicGenerator ( ) , null , new ReducerOptions ( ) ) ; }
For a {@link SystemInputDef system input definition}, returns a set of {@link GeneratorSet test case generators}
that {@link #reduce( SystemInputDef, GeneratorSet, SystemTestDef, ReducerOptions) reduces}
the number of test cases normally generated, using default {@link ReducerOptions options}.
Returns <CODE>Optional.empty()</CODE> if test cases were not reduced.