docs: public void setPropagatingVgws(java.util.Collection<PropagatingVgw> propagatingVgws) {
          if (propagatingVgws == null) {
              this.propagatingVgws = null;
              return;
          }
  
          this.propagatingVgws = new com.amazonaws.internal.SdkInternalList<PropagatingVgw>(propagatingVgws);
      }