docs: public RouteTable withPropagatingVgws(PropagatingVgw... propagatingVgws) {
          if (this.propagatingVgws == null) {
              setPropagatingVgws(new com.amazonaws.internal.SdkInternalList<PropagatingVgw>(propagatingVgws.length));
          }
          for (PropagatingVgw ele : propagatingVgws) {
              this.propagatingVgws.add(ele);
          }
          return this;
      }