private com.google.protobuf.RepeatedFieldBuilderV3<
              com.google.cloud.tpu.v2.QueuedResource.Tpu.NodeSpec,
              com.google.cloud.tpu.v2.QueuedResource.Tpu.NodeSpec.Builder,
              com.google.cloud.tpu.v2.QueuedResource.Tpu.NodeSpecOrBuilder>
          getNodeSpecFieldBuilder() {
        if (nodeSpecBuilder_ == null) {
          nodeSpecBuilder_ =
              new com.google.protobuf.RepeatedFieldBuilderV3<
                  com.google.cloud.tpu.v2.QueuedResource.Tpu.NodeSpec,
                  com.google.cloud.tpu.v2.QueuedResource.Tpu.NodeSpec.Builder,
                  com.google.cloud.tpu.v2.QueuedResource.Tpu.NodeSpecOrBuilder>(
                  nodeSpec_, ((bitField0_ & 0x00000001) != 0), getParentForChildren(), isClean());
          nodeSpec_ = null;
        }
        return nodeSpecBuilder_;
      }
<pre>
Optional. The TPU node(s) being requested.
</pre>

<code>
repeated .google.cloud.tpu.v2.QueuedResource.Tpu.NodeSpec node_spec = 1 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-tpu/proto-google-cloud-tpu-v2/src/main/java/com/google/cloud/tpu/v2/QueuedResource.java