public void visitedLinks(Visitor<LinkRelevance> visitor) throws Exception {
        urlRelevance.visitTuples((Tuple<LinkRelevance> tuple) -> {
            if (tuple.getValue().getRelevance() < 0) {
                visitor.visit(tuple.getValue());
            }
        });
    }
DEPRECATED: may cause OutOfMemoryError on large crawls. TODO: Provide an method that uses an
iterator, and/or load just a sample of the data.
ache/src/main/java/achecrawler/link/frontier/Frontier.java