class Transformers {

   static MessageBody inputToQueryMessage(JsonElement payload) {
      Set<String> addresses = ImmutableSet.of();
      if(payload != null) {
         QueryPayload query = GSON.fromJson(payload, QueryPayload.class);
         addresses = devicesToAddresses(query.devicesAsBeans());
      }
      return GoogleService.QueryRequest.builder()
            .withAddresses(addresses)
            .build();
   }

   private  Transformers();

}