code: private List<Usage> getUsageCalls(final Sid accountSid, Usage.Category category, DateTime startDate, DateTime endDate, final String queryName) {
      return getUsageCalls(accountSid, category, startDate, endDate, "", queryName);
    }
docs: /*
  @Override
  public List<Usage> getUsageToday(final Sid accountSid, Usage.Category category, DateTime startDate, DateTime endDate) {
  return getUsageCalls(accountSid, category, startDate, endDate, "getTodayCalls");
  }
  
  @Override
  public List<Usage> getUsageYesterday(final Sid accountSid, Usage.Category category, DateTime startDate, DateTime endDate) {
  return getUsageCalls(accountSid, category, startDate, endDate, "getYesterdayCalls");
  }
  
  @Override
  public List<Usage> getUsageThisMonth(final Sid accountSid, Usage.Category category, DateTime startDate, DateTime endDate) {
  return getUsageCalls(accountSid, category, startDate, endDate, "getThisMonthCalls");
  }
  
  @Override
  public List<Usage> getUsageLastMonth(final Sid accountSid, Usage.Category category, DateTime startDate, DateTime endDate) {
  return getUsageCalls(accountSid, category, startDate, endDate, "getLastMonthCalls");
  }