private OntologyServiceResponse.Result findOntologyEntitiesPaged(String serviceSessionUrl,
          String keywords, int page, int conceptsPerPage) throws IOException {
    Map<String, ?> request = ImmutableMap
            .of("findEntitiesPaged", new Object[] { keywords, page, conceptsPerPage });
    String response = postRequest(serviceSessionUrl, gson.toJson(request));
    return gson.fromJson(response, OntologyServiceResponse.class).getResult();
  }