@method("usage")
public Map<String, Object> usage(@QueryParam("period") String period) {
if (expectedPeriod != null) {
if (!expectedPeriod.toString().equalsIgnoreCase(period)) {
throw new WebApplicationException(HttpResponseStatus.BAD_REQUEST);
}
}
Map<String, Object> map = new HashMap<>();
map.put("start", start);
map.put("end", end);