private void advance() {
                this.nextResult = null;
                while (iterator.hasNext()) {
                    final S s = iterator.next();
                    if (predicate.test(s)) {
                        this.nextResult = s;
                        return;
                    }
                }
            }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/util/iterator/IteratorUtils.java