code: public ListRoutesResult withRoutes(RouteRef... routes) {
          if (this.routes == null) {
              setRoutes(new java.util.ArrayList<RouteRef>(routes.length));
          }
          for (RouteRef ele : routes) {
              this.routes.add(ele);
          }
          return this;
      }
docs: <p>
  The list of existing routes for the specified service mesh and virtual router.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setRoutes(java.util.Collection)} or {@link #withRoutes(java.util.Collection)} if you want to override the
  existing values.
  </p>
  
  @param routes
  The list of existing routes for the specified service mesh and virtual router.
  @return Returns a reference to this object so that method calls can be chained together.