private void maybeForceBuilderInitialization() {
          if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {
            getMultiNodeParamsFieldBuilder();
            getNodeFieldBuilder();
          }
        }
<pre>
Details of the TPU node(s) being requested. Users can request either a
single node or multiple nodes.
NodeSpec provides the specification for node(s) to be created.
</pre>

Protobuf type {@code google.cloud.tpu.v2alpha1.QueuedResource.Tpu.NodeSpec}
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/QueuedResource.java