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