code: public void setRegionOrder(java.util.Collection<String> regionOrder) {
          if (regionOrder == null) {
              this.regionOrder = null;
              return;
          }
  
          this.regionOrder = new com.amazonaws.internal.SdkInternalList<String>(regionOrder);
      }
docs: <p>
  The order of the regions in where you want to perform the stack operation.
  </p>
  
  @param regionOrder
  The order of the regions in where you want to perform the stack operation.