public com.google.protobuf.ByteString getEtagBytes() {
      java.lang.Object ref = etag_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        etag_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Optional. If set, the request will be rejected if the latest version of the
workstation on the server does not have this ETag.
</pre>

<code>string etag = 3 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for etag.
java-workstations/proto-google-cloud-workstations-v1/src/main/java/com/google/cloud/workstations/v1/StopWorkstationRequest.java