public PartialJoinWithLeftKey(IEnumerable <TLeft> leftCollection, IEnumerable <TRight> rightCollection, Func <TLeft, TKey> leftKeyFunc, IJoinFactory factory)
 {
     _leftCollection  = leftCollection;
     _rightCollection = rightCollection;
     _leftKeyFunc     = leftKeyFunc;
     _factory         = factory;
 }
 public PartialJoinWithRightList(IEnumerable <TLeft> leftCollection, IEnumerable <TRight> rightCollection, IJoinFactory factory)
 {
     _leftCollection  = leftCollection;
     _rightCollection = rightCollection;
     _factory         = factory;
 }