code: def __getSheet(self, name):
          ''' get a sheet by name '''
          if not self.sheetExsit(name):
              raise UfException(Errors.SHEET_NAME_INVALID, "Can't find a sheet named %s" % name)
  
          return self.__sheetNameDict[namef __getSheet(self, name):
          ''' get a sheet by name '''
          if not self.sheetExsit(name):
              raise UfException(Errors.SHEET_NAME_INVALID, "Can't find a sheet named %s" % name)
  
          return self.__sheetNameDict[name]
docs: get a sheet by name