public com.google.protobuf.ByteString getPageTokenBytes() {
      java.lang.Object ref = pageToken_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        pageToken_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Token identifying the page of results to return. If provided, use the
value of the `next_page_token` field from a previous request.
</pre>

<code>string page_token = 4;</code>

@return The bytes for pageToken.
java-trace/proto-google-cloud-trace-v1/src/main/java/com/google/devtools/cloudtrace/v1/ListTracesRequest.java