Returns an iterator over the elements in this deque in proper sequence.
The elements will be returned in order from first (head) to last (tail).
The returned {@code Iterator} is a "weakly consistent" iterator that
will never throw {@link java.util.ConcurrentModificationException
ConcurrentModificationException},
and guarantees to traverse elements as they existed upon
construction of the iterator, and may (but is not guaranteed to)
reflect any modifications subsequent to construction.
@return an iterator over the elements in this deque in proper sequence
Returns an iterator over the elements in this deque in proper sequence. The elements will be returned in order from first (head) to last (tail). The returned {@code Iterator} is a "weakly consistent" iterator that will never throw {@link java.util.ConcurrentModificationException ConcurrentModificationException}, and guarantees to traverse elements as they existed upon construction of the iterator, and may (but is not guaranteed to) reflect any modifications subsequent to construction.
@return an iterator over the elements in this deque in proper sequence