private com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.tpu.v2alpha1.Node,
                com.google.cloud.tpu.v2alpha1.Node.Builder,
                com.google.cloud.tpu.v2alpha1.NodeOrBuilder>
            getNodeFieldBuilder() {
          if (nodeBuilder_ == null) {
            nodeBuilder_ =
                new com.google.protobuf.SingleFieldBuilderV3<
                    com.google.cloud.tpu.v2alpha1.Node,
                    com.google.cloud.tpu.v2alpha1.Node.Builder,
                    com.google.cloud.tpu.v2alpha1.NodeOrBuilder>(
                    getNode(), getParentForChildren(), isClean());
            node_ = null;
          }
          return nodeBuilder_;
        }
<pre>
Required. The node.
</pre>

<code>.google.cloud.tpu.v2alpha1.Node node = 3 [(.google.api.field_behavior) = REQUIRED];
</code>
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/QueuedResource.java