/** Marks the given visitor accepter as possibly being used. */
protected void markAsPossiblyUsed(VisitorAccepter visitorAccepter) {
visitorAccepter.setVisitorInfo(POSSIBLY_USED);
}
/** Clears any usage marks from the given visitor accepter. */
protected void markAsUnused(VisitorAccepter visitorAccepter) {
visitorAccepter.setVisitorInfo(null);
}
/** Marks the given visitor accepter as being used. */
protected void markAsUsed(VisitorAccepter visitorAccepter) {
visitorAccepter.setVisitorInfo(USED);
}