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>
Keep the persistent disk when deleting the workstation.
An administrator must manually delete the disk.
</pre>

<code>RETAIN = 2;</code>
java-workstations/proto-google-cloud-workstations-v1/src/main/java/com/google/cloud/workstations/v1/WorkstationConfig.java