@Override
    public T next() {
        if (!this.alive)
            throw FastNoSuchElementException.instance();
        else {
            this.alive = false;
            return t;
        }
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/util/iterator/SingleIterator.java