@Override
    public MergeEdgeStep<S> clone() {
        final MergeEdgeStep<S> clone = (MergeEdgeStep<S>) super.clone();
        clone.outVTraversal = outVTraversal != null ? outVTraversal.clone() : null;
        clone.inVTraversal = inVTraversal != null ? inVTraversal.clone() : null;
        return clone;
    }
Gets the traversal that will be used to provide the {@code Map} that will be used to identify the Direction.IN
vertex during merge.
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/MergeEdgeStep.java