public final int getNumber() {
      if (this == UNRECOGNIZED) {
        throw new java.lang.IllegalArgumentException(
            "Can't get the number of an unknown enum value.");
      }
      return value;
    }
<pre>
TPU node has unknown state after a failed repair.
</pre>

<code>UNKNOWN = 16;</code>
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/Node.java