@Override
    protected Traverser.Admin<E> processNextStart() throws NoSuchElementException {
        while (true) {
            if (this.previousIterator.hasNext())
                return this.previousIterator.next();
            this.previousIterator = this.traverserStepIdAndLabelsSetByChild ? this.computerAlgorithm() : this.standardAlgorithm();
        }
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/util/ComputerAwareStep.java