code: public Object[] toArray() {
          fullyLock();
          try {
              int size = count.get();
              Object[] a = new Object[size];
              int k = 0;
              for (Node<E> p = head.next; p != null; p = p.next)
                  a[k++] = p.item;
              return a;
          } finally {
              fullyUnlock();
          }
      }
docs: Returns an array containing all of the elements in this queue, in
  proper sequence.
  
  <p>The returned array will be "safe" in that no references to it are
  maintained by this queue.  (In other words, this method must allocate
  a new array).  The caller is thus free to modify the returned array.
  
  <p>This method acts as bridge between array-based and collection-based
  APIs.
  
  @return an array containing all of the elements in this queue