def _estimate_label_shape(self):
        """Helper function to estimate label shape"""
        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])
Helper function to estimate label shape