Differences between version #2328 and #3922

5a6
> A double ended queue.  Elements can be added to either end.  The deque is thread safe.
14a16
> Add and element to the end of the deque.
19a22
> Removes the first element and returns it.  If ''block'' is true and the deque is empty, the function blocks until a function is added.  If ''block'' is false and the deque is empty, the function returns ''null'' immediately.
24a28
> Push an element into the beginning of the deque.