private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.tpu.v1.Node,
            com.google.cloud.tpu.v1.Node.Builder,
            com.google.cloud.tpu.v1.NodeOrBuilder>
        getNodeFieldBuilder() {
      if (nodeBuilder_ == null) {
        nodeBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.tpu.v1.Node,
                com.google.cloud.tpu.v1.Node.Builder,
                com.google.cloud.tpu.v1.NodeOrBuilder>(
                getNode(), getParentForChildren(), isClean());
        node_ = null;
      }
      return nodeBuilder_;
    }
<pre>
Required. The node.
</pre>

<code>.google.cloud.tpu.v1.Node node = 3 [(.google.api.field_behavior) = REQUIRED];</code>
java-tpu/proto-google-cloud-tpu-v1/src/main/java/com/google/cloud/tpu/v1/CreateNodeRequest.java