docs: static void traverseToRole(
              GraphTraversal<?, Edge> traversal, @Nullable Variable role, Schema.EdgeProperty edgeProperty,
              Collection<Variable> vars) {
          if (role != null) {
              Variable edge = new Variable();
              traversal.as(edge.symbol());
              Fragments.outSubs(Fragments.traverseSchemaConceptFromEdge(traversal, edgeProperty));
              assignVar(traversal, role, vars).select(edge.symbol());
          }
      }