@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(parent_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 1, parent_);
    }
    if (pageSize_ != 0) {
      output.writeInt32(2, pageSize_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(pageToken_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 3, pageToken_);
    }
    getUnknownFields().writeTo(output);
  }
<pre>
A token identifying a page of results to be returned. This is the value
of `nextPageToken` returned in a previous reference image list request.

Defaults to the first page if not specified.
</pre>

<code>string page_token = 3;</code>

@return The bytes for pageToken.
java-vision/proto-google-cloud-vision-v1p3beta1/src/main/java/com/google/cloud/vision/v1p3beta1/ListReferenceImagesRequest.java