code: def _write_ieeg_channels(output_file, data):
      
      CHAN_TYPE = 'ECOG'
      CHAN_UNIT = 'µV'
  
      with output_file.open('w') as f:
          f.write('name\ttype\tunits\tsampling_frequency\tlow_cutoff\thigh_cutoff\tnotch\treference\n')
          for one_chan in data.chan[0]:
              f.write('\t'.join([
                  one_chan,
                  CHAN_TYPE,
                  CHAN_UNIT,
                  f'{data.s_freq:f}',
                  'n/a',
                  'n/a',
                  'n/a',
                  'n/a',
                  ]) + '\n')
docs: TODO
      ----
      Make sure that the channels in all the trials are the same.