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. This checksum is computed by the server based on the value of
other fields, and might be sent on update requests to ensure the client has
an up-to-date value before proceeding.
</pre>

<code>string etag = 17 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for etag.
java-workspaceevents/proto-google-cloud-workspaceevents-v1/src/main/java/com/google/apps/events/subscriptions/v1/Subscription.java