internal All(ActiveFields source) { m_Source = source; }
internal Base(ActiveFields source) { m_Source = source; }
internal NoPermutation(ActiveFields source) { m_Source = source; }
internal ForPermutationIndex(ActiveFields source, int index) { m_Source = source; m_PermutationIndex = index; }
internal AllPermutations(ActiveFields source) { m_Source = source; }