def METHOD_NAME(self, doc):
    uid = doc['uid']
    run_start_uid = doc['run_start']
    groupname = 'desc_' + uid.replace('-', '_')
    fp = self._runstarts[run_start_uid]
    with h5py.File(fp, 'a') as f:
        g = f.create_group(groupname)
        g.create_dataset('uid', shape=(0,), maxshape=(None,), dtype='S36')
        g.create_dataset('time', shape=(0,), maxshape=(None,),
                         dtype='float64')
        g.create_dataset('seq_num', shape=(0,), maxshape=(None,))
        g.create_group('data')
        g.create_group('timestamps')
        for key in doc['data_keys']:
            # Create an empty, resizable dataset for each key.
            g['timestamps'].create_dataset(key, shape=(0,),
                                           maxshape=(None,),
                                           dtype='float64')
    self._descriptors[uid] = run_start_uid