code: public Sheet sortSheet(long sheetId, SortSpecifier sortSpecifier) throws SmartsheetException {
          return this.sortSheet(sheetId, sortSpecifier, null);
      }
docs: Sort a sheet according to the sort criteria.
  
  It mirrors to the following Smartsheet REST API method: POST /sheet/{sheetId}/sort
  
  Exceptions:
  - IllegalArgumentException : if any argument is null
  - InvalidRequestException : if there is any problem with the REST API request
  - AuthorizationException : if there is any problem with the REST API authorization(access token)
  - ServiceUnavailableException : if the REST API service is not available (possibly due to rate limiting)
  - SmartsheetRestException : if there is any other REST API related error occurred during the operation
  - SmartsheetException : if there is any other error occurred during the operation
  
  @param sheetId the sheet id
  @param sortSpecifier the sort criteria
  @return the update request object
  @throws SmartsheetException the smartsheet exception