code: public <U> U makeRequest(final TypeReference<U> typeReference, final BackendCaller<? super E, ? super T> backendCaller) throws HodErrorException {
          checkTokenProxyService();
          return makeRequest(tokenProxyService.getTokenProxy(), typeReference, backendCaller);
      }
docs: Makes a request to HP Haven OnDemand using a TokenProxy provided by a {@link TokenProxyService}, converting the
  response body to the type specified by the type reference.
  @param typeReference The desired type of the value returned by HP Haven OnDemand
  @param backendCaller Makes the request to HP Haven OnDemand
  @param <U> The desired type of the value returned by HP Haven OnDemand
  @return An object representing the output from HP Haven OnDemand
  @throws HodErrorException
  @throws NullPointerException If a TokenProxyService has not been configured