public static <S, E> void insertAfterStep(final Step<S, E> insertStep, final Step<?, S> beforeStep, final Traversal.Admin<?, ?> traversal) {
        traversal.addStep(stepIndex(beforeStep, traversal) + 1, insertStep);
    }
Insert a step after a specified step instance.

@param insertStep the step to insert
@param beforeStep the step to insert the new step after
@param traversal  the traversal on which the action should occur
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/util/TraversalHelper.java