code: def _estimate_label_shape(self):
          
          max_count = 0
          self.reset()
          try:
              while True:
                  label, _ = self.next_sample()
                  label = self._parse_label(label)
                  max_count = max(max_count, label.shape[0])
          except StopIteration:
              pass
          self.reset()
          return (max_count, label.shape[1])
docs: Helper function to estimate label shape