code: def _hierarchy_bounds(intervals_hier):
      '''Compute the covered time range of a hierarchical segmentation.
  
      Parameters
      ----------
      intervals_hier : list of ndarray
          A hierarchical segmentation, encoded as a list of arrays of segment
          intervals.
  
      Returns
      -------
      t_min : float
      t_max : float
          The minimum and maximum times spanned by the annotation
      '''
      boundaries = list(itertools.chain(*list(itertools.chain(*intervals_hier))))
  
      return min(boundaries), max(boundariesf _hierarchy_bounds(intervals_hier):
      '''Compute the covered time range of a hierarchical segmentation.
  
      Parameters
      ----------
      intervals_hier : list of ndarray
          A hierarchical segmentation, encoded as a list of arrays of segment
          intervals.
  
      Returns
      -------
      t_min : float
      t_max : float
          The minimum and maximum times spanned by the annotation
      '''
      boundaries = list(itertools.chain(*list(itertools.chain(*intervals_hier))))
  
      return min(boundaries), max(boundaries)
docs: Compute the covered time range of a hierarchical segmentation.
  
      Parameters
      ----------
      intervals_hier : list of ndarray
          A hierarchical segmentation, encoded as a list of arrays of segment
          intervals.
  
      Returns
      -------
      t_min : float
      t_max : float
          The minimum and maximum times spanned by the annotation