code: def _read_frame(self, blocksize):
          
          try:
              read_func = _fr_type_map[self.channel_type][0]
              dtype = _fr_type_map[self.channel_type][1]
              data = read_func(self.stream, self.channel_name,
                               self.read_pos, int(blocksize), 0)
              return TimeSeries(data.data.data, delta_t=data.deltaT,
                                epoch=self.read_pos,
                                dtype=dtype)
          except Exception:
              raise RuntimeError('Cannot read {0} frame data'.format(self.channel_name))
docs: Try to read the block of data blocksize seconds long
  
          Parameters
          ----------
          blocksize: int
              The number of seconds to attempt to read from the channel
  
          Returns
          -------
          data: TimeSeries
              TimeSeries containg 'blocksize' seconds of frame data
  
          Raises
          ------
          RuntimeError:
              If data cannot be read for any reason