package class4_3_Queues_051;

public interface Queue<E> {
    /** @return item removed from the front (head) of the queue*/
    E poll();

    /** @param element Item to be inserted at the back (tail) of the queue */
    boolean offer(E element);

    /** @return item at front of queue (without removing) */
    E peek();

    /** @return true if no items in queue */
    boolean isEmpty();
}