@Override
    protected Traverser.Admin<S> processNextStart() throws NoSuchElementException {
        while (true) {
            if (this.currentIterator.hasNext())
                return this.currentIterator.next();
            else {
                final ComputerResult result = this.starts.next().get();
                this.currentIterator = attach(result.memory().exists(TraversalVertexProgram.HALTED_TRAVERSERS)
                        ? result.memory().<TraverserSet<S>>get(TraversalVertexProgram.HALTED_TRAVERSERS).iterator()
                        : EmptyIterator.instance(), result.graph());
            }
        }
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/traversal/step/map/ComputerResultStep.java