docs: def readCell(self, row, col):
          ''' read a cell'''
          try:
              if self.__sheet is None:
                  self.openSheet(super(ExcelRead, self).DEFAULT_SHEET)
  
              return self.__sheet.cell(row, col).value
          except BaseException as excp:
              raise UfException(Errors.UNKNOWN_ERROR, "Unknown Error in Excellib.readCell %s" % excp)