docs: @BetaApi
    public final Operation addNodesNodeGroup(
        ProjectZoneNodeGroupName nodeGroup,
        NodeGroupsAddNodesRequest nodeGroupsAddNodesRequestResource) {
  
      AddNodesNodeGroupHttpRequest request =
          AddNodesNodeGroupHttpRequest.newBuilder()
              .setNodeGroup(nodeGroup == null ? null : nodeGroup.toString())
              .setNodeGroupsAddNodesRequestResource(nodeGroupsAddNodesRequestResource)
              .build();
      return addNodesNodeGroup(request);
    }