private ListIterator<E> listIterator(int index) {
        return new ImplicitLinkedHashCollectionIterator(index);
    }
Returns an iterator that will yield every element in the set.
The elements will be returned in the order that they were inserted in.

Do not modify the set while you are iterating over it (except by calling
remove on the iterator itself, of course.)
clients/src/main/java/org/apache/kafka/common/utils/ImplicitLinkedHashCollection.java