private int nextCursor = -1;
    private int expectedModCount = modCount;
    // The same element is not allowed in both forgetMeNot and skipMe, but duplicates are allowed in
    // either of them, up to the same multiplicity as the queue.
    @CheckForNull private Queue<E> forgetMeNot;
    @CheckForNull private List<E> skipMe;
    @CheckForNull private E lastFromForgetMeNot;
    private boolean canRemove;

    @Override

 * the same single element. The total number of occurrences of an element in a multiset is called
 * the <i>count</i> of that element (the terms "frequency" and "multiplicity" are equivalent, but
 * not used in this API). Since the count of an element is represented as an {@code int}, a multiset
 * may never contain more than {@link Integer#MAX_VALUE} occurrences of any one element.
 *

 * the same single element. The total number of occurrences of an element in a multiset is called
 * the <i>count</i> of that element (the terms "frequency" and "multiplicity" are equivalent, but
 * not used in this API). Since the count of an element is represented as an {@code int}, a multiset
 * may never contain more than {@link Integer#MAX_VALUE} occurrences of any one element.
 *

    private int nextCursor = -1;
    private int expectedModCount = modCount;
    // The same element is not allowed in both forgetMeNot and skipMe, but duplicates are allowed in
    // either of them, up to the same multiplicity as the queue.
    @CheckForNull private Queue<E> forgetMeNot;
    @CheckForNull private List<E> skipMe;
    @CheckForNull private E lastFromForgetMeNot;
    private boolean canRemove;

    @Override