@Override
        public E previous() {
            Element prev = indexToElement(head, elements, cur.prev());
            if (prev == head) {
                throw new NoSuchElementException();
            }
            cur = prev;
            --index;
            lastReturned = cur;
            @SuppressWarnings("unchecked")
            E returnValue = (E) cur;
            return returnValue;
        }
A static empty array used to avoid object allocations when the capacity is zero.
clients/src/main/java/org/apache/kafka/common/utils/ImplicitLinkedHashCollection.java