code: @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);
    }
docs: Adds specified number of nodes to the node group.
  
  <p>Sample code:
  
  <pre><code>
  try (NodeGroupClient nodeGroupClient = NodeGroupClient.create()) {
  ProjectZoneNodeGroupName nodeGroup = ProjectZoneNodeGroupName.of("[PROJECT]", "[ZONE]", "[NODE_GROUP]");
  NodeGroupsAddNodesRequest nodeGroupsAddNodesRequestResource = NodeGroupsAddNodesRequest.newBuilder().build();
  Operation response = nodeGroupClient.addNodesNodeGroup(nodeGroup, nodeGroupsAddNodesRequestResource);
  }
  </code></pre>
  
  @param nodeGroup Name of the NodeGroup resource.
  @param nodeGroupsAddNodesRequestResource
  @throws com.google.api.gax.rpc.ApiException if the remote call fails