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;
 }