@java.lang.Override
    public final Builder setUnknownFields(final com.google.protobuf.UnknownFieldSet unknownFields) {
      return super.setUnknownFields(unknownFields);
    }
<pre>
Token to retrieve the next page of results, or empty if there are no more
results in the list.
</pre>

<code>string next_page_token = 2;</code>

@param value The bytes for nextPageToken to set.
@return This builder for chaining.
java-vision/proto-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/ListProductSetsResponse.java