public com.google.protobuf.ByteString getOrderByBytes() {
      java.lang.Object ref = orderBy_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        orderBy_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Hint for how to order the results.
</pre>

<code>string order_by = 5;</code>

@return The bytes for orderBy.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/ListSeriesRequest.java