public IEnumerator <IEnumerable <T> > GetEnumerator()
{
if (_startLevel + 1 == _setOfValues.Length)
{
yield return(Enumerable.Repeat(_setOfValues.ElementAt(_startLevel), 1));
}
else
{
PermutationGenerator <T> permutations = new PermutationGenerator <T>(_setOfValues, _startLevel + 1);
foreach (var permutation in permutations.ToList())
{
foreach (var newPermutation in Mix(_setOfValues[_startLevel], permutation).ToList())
{
yield return(newPermutation);
}
}
}
}