code: def _batchify(self, batch_data, batch_label, start=0):
          
          i = start
          batch_size = self.batch_size
          try:
              while i < batch_size:
                  label, s = self.next_sample()
                  data = self.imdecode(s)
                  try:
                      self.check_valid_image(data)
                  except RuntimeError as e:
                      logging.debug('Invalid image, skipping:  %s', str(e))
                      continue
                  data = self.augmentation_transform(data)
                  assert i < batch_size, 'Batch size must be multiples of augmenter output length'
                  batch_data[i] = self.postprocess_data(data)
                  batch_label[i] = label
                  i += 1
          except StopIteration:
              if not i:
                  raise StopIteration
          return i
docs: Helper function for batchifying data