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>
Attaches the disk in read-only mode. Multiple TPU nodes can attach
a disk in read-only mode at a time.
</pre>

<code>READ_ONLY = 2;</code>
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/AttachedDisk.java