@Override
    public void merge(final Traverser.Admin<?> other) {
        super.merge(other);
        this.bulk = this.bulk + other.bulk();
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/traverser/B_O_Traverser.java