code: def return_hdr(self):
          
          with open(self.filename, 'r') as f:
              orig = load(f)
  
          start_time = datetime.strptime(orig['start_time'],
                                         '%Y-%m-%d %H:%M:%S.%f')
          self.memshape = (len(orig['chan_name']),
                           orig['n_samples'])
          self.dtype = orig.get('dtype', 'float64')
  
          return (orig['subj_id'], start_time, orig['s_freq'], orig['chan_name'],
                  orig['n_samples'], orig)
docs: Return the header for further use.
  
          Returns
          -------
          subj_id : str
              subject identification code
          start_time : datetime
              start time of the dataset
          s_freq : float
              sampling frequency
          chan_name : list of str
              list of all the channels
          n_samples : int
              number of samples in the dataset
          orig : dict
              the json file