internal void Add(WeakReferenceHandler reference)
 {
     lock (this)
     {
         _list = new List4(_list, reference);
     }
 }

        internal void Poll(ObjectContainerBase objectContainer) {
            List4 remove = null;
            lock(this){
                System.Collections.IEnumerator i = new Iterator4Impl(_list);
                _list = null;
                while(i.MoveNext()){
					WeakReferenceHandler refHandler = (WeakReferenceHandler)i.Current;
                    if(refHandler.IsAlive){
                        _list = new List4(_list, refHandler);
                    }else{
                        remove = new List4(remove, refHandler.ObjectReference);
                    }
                }
            }
            System.Collections.IEnumerator j = new Iterator4Impl(remove);
            while (j.MoveNext())
            {
                lock (objectContainer.Lock())
                {
                    if (objectContainer.IsClosed())
                    {
                        return;
                    }
                    objectContainer.RemoveFromAllReferenceSystems(j.Current);
                }
            }
        }

		private void RemoveNext()
		{
			_next = ((List4)_next._next);
			if (_next == null)
			{
				_insertionPoint = null;
			}
		}

 public void PlayCommandList(List4 commandList)
 {
     while (commandList != null)
     {
         IIoCommand ioCommand = (IIoCommand)commandList._element;
         ioCommand.Replay(_bin);
         commandList = commandList._next;
     }
 }

		public virtual object Pop()
		{
			if (_tail == null)
			{
				throw new InvalidOperationException();
			}
			object res = _tail._element;
			_tail = ((List4)_tail._next);
			return res;
		}

		public virtual bool MoveNext()
		{
			if (_next == null)
			{
				_current = Iterators.NoElement;
				return false;
			}
			_current = ((object)_next._element);
			_next = ((List4)_next._next);
			return true;
		}

 public static int Size(List4 list)
 {
     var counter = 0;
     var nextList = list;
     while (nextList != null)
     {
         counter++;
         nextList = nextList._next;
     }
     return counter;
 }

		private void DoPrepend(object element)
		{
			if (_first == null)
			{
				DoAdd(element);
			}
			else
			{
				_first = new List4(_first, element);
				_size++;
			}
		}

		public void Add(object obj)
		{
			List4 newNode = new List4(null, obj);
			if (_insertionPoint == null)
			{
				_next = newNode;
			}
			else
			{
				_insertionPoint._next = newNode;
			}
			_insertionPoint = newNode;
		}

		private void DoAdd(object element)
		{
			if (_last == null)
			{
				_first = new List4(element);
				_last = _first;
			}
			else
			{
				_last._next = new List4(element);
				_last = ((List4)_last._next);
			}
			_size++;
		}

 public List4 ReadCommandList()
 {
     List4 list = null;
     StreamReader reader = new StreamReader(_logFilePath);
     String line = null;
     while ((line = reader.ReadLine()) != null)
     {
         IIoCommand ioCommand = ReadLine(line);
         if (ioCommand != null)
         {
             list = new List4(list, ioCommand);
         }
     }
     reader.Close();
     return list;
 }

			public _Iterator4Impl_82(NonblockingQueue _enclosing, List4 origInsertionPoint, List4
				 origNext, List4 baseArg1) : base(baseArg1)
			{
				this._enclosing = _enclosing;
				this.origInsertionPoint = origInsertionPoint;
				this.origNext = origNext;
			}

		public static IEnumerator Iterate(List4 list)
		{
			if (list == null)
			{
				return EmptyIterator;
			}
			Collection4 collection = new Collection4();
			while (list != null)
			{
				collection.Add(list._element);
				list = ((List4)list._next);
			}
			return collection.GetEnumerator();
		}

		public Iterator4Impl(List4 first)
		{
			_first = first;
			_next = first;
			_current = Iterators.NoElement;
		}

		// virtual
		internal virtual void ExchangeConstraint(Db4objects.Db4o.Internal.Query.Processor.QCon
			 a_exchange, Db4objects.Db4o.Internal.Query.Processor.QCon a_with)
		{
			List4 previous = null;
			List4 current = _children;
			while (current != null)
			{
				if (current._element == a_exchange)
				{
					if (previous == null)
					{
						_children = ((List4)current._next);
					}
					else
					{
						previous._next = ((List4)current._next);
					}
				}
				previous = current;
				current = ((List4)current._next);
			}
			_children = new List4(_children, a_with);
		}

		internal virtual void StillToSet(Transaction transaction, ObjectReference @ref, IUpdateDepth
			 updateDepth)
		{
			if (StackIsSmall())
			{
				if (@ref.ContinueSet(transaction, updateDepth))
				{
					return;
				}
			}
			_stillToSet = new List4(_stillToSet, new ObjectContainerBase.PendingSet(transaction
				, @ref, updateDepth));
		}

		internal virtual Db4objects.Db4o.Internal.Query.Processor.QCon AddConstraint(Db4objects.Db4o.Internal.Query.Processor.QCon
			 a_child)
		{
			_children = new List4(_children, a_child);
			return a_child;
		}

		public Collection4Iterator(Collection4 collection, List4 first) : base(first)
		{
			_collection = collection;
			_initialVersion = CurrentVersion();
		}

		public static IEnumerator Revert(IEnumerator iterator)
		{
			iterator.Reset();
			List4 tail = null;
			while (iterator.MoveNext())
			{
				tail = new List4(tail, iterator.Current);
			}
			return Iterate(tail);
		}

 internal virtual void AddDependant(QCandidate
     a_candidate)
 {
     _dependants = new List4(_dependants, a_candidate);
 }