@Override
    public boolean hasNext() {
        if (this.bulker.isEmpty())
            this.fillBulker();
        return !this.bulker.isEmpty();
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-server/src/main/java/org/apache/tinkerpop/gremlin/server/util/TraverserIterator.java