code: 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;
      }
docs: <p>
  Any virtual private gateway (VGW) propagating routes.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setPropagatingVgws(java.util.Collection)} or {@link #withPropagatingVgws(java.util.Collection)} if you
  want to override the existing values.
  </p>
  
  @param propagatingVgws
  Any virtual private gateway (VGW) propagating routes.
  @return Returns a reference to this object so that method calls can be chained together.