public Builder distanceProperty(final String distance) {
            //noinspection unchecked
            return distance != null
                    ? distanceTraversal(__.values(distance)) // todo: (Traversal) new ElementValueTraversal<>(distance)
                    : distanceTraversal(DEFAULT_DISTANCE_TRAVERSAL.getPure());
        }
Move any valid path into the VP's memory.
@param vertex The current vertex.
@param memory The VertexProgram's memory.
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/search/path/ShortestPathVertexProgram.java