public T peek() {
        return nextValue;
    }
Peek at the next value in the Iterator. Calling this method multiple
times will return the same element without advancing this Iterator. The
value returned by this method will be the next item returned by
{@code next()}.

@return The next value in this {@code Iterator}
clients/src/main/java/org/apache/kafka/common/utils/CircularIterator.java