public final boolean doUntil(final Traverser.Admin<S> traverser, boolean utilFirst) {
        return utilFirst == this.untilFirst && null != this.untilTraversal && TraversalUtil.test(traverser, this.untilTraversal);
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/branch/RepeatStep.java