code: def get_index(self, name_subdevice) -> int:
          
          try:
              return self.dict_[name_subdevice]
          except KeyError:
              raise OSError(
                  'No data for sequence `%s` and (sub)device `%s` '
                  'in NetCDF file `%s` available.'
                  % (self.name_sequence,
                     name_subdevice,
                     self.name_ncfile))
docs: Item access to the wrapped |dict| object with a specialized
          error message.