private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.tpu.v2alpha1.ShieldedInstanceConfig,
            com.google.cloud.tpu.v2alpha1.ShieldedInstanceConfig.Builder,
            com.google.cloud.tpu.v2alpha1.ShieldedInstanceConfigOrBuilder>
        getShieldedInstanceConfigFieldBuilder() {
      if (shieldedInstanceConfigBuilder_ == null) {
        shieldedInstanceConfigBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.tpu.v2alpha1.ShieldedInstanceConfig,
                com.google.cloud.tpu.v2alpha1.ShieldedInstanceConfig.Builder,
                com.google.cloud.tpu.v2alpha1.ShieldedInstanceConfigOrBuilder>(
                getShieldedInstanceConfig(), getParentForChildren(), isClean());
        shieldedInstanceConfig_ = null;
      }
      return shieldedInstanceConfigBuilder_;
    }
<pre>
Shielded Instance options.
</pre>

<code>.google.cloud.tpu.v2alpha1.ShieldedInstanceConfig shielded_instance_config = 45;</code>
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/Node.java