code: def _total_rectangles(tree):
      '''
      Calculate the total number of segments that are required
      for the dendrogram. There is a vertical line for each segment
      and two horizontal line at each branching point
      '''
      return sum(len(sec.children) + sec.points.shape[0] - 1
                 for sec in tree.iter_sections()f _total_rectangles(tree):
      '''
      Calculate the total number of segments that are required
      for the dendrogram. There is a vertical line for each segment
      and two horizontal line at each branching point
      '''
      return sum(len(sec.children) + sec.points.shape[0] - 1
                 for sec in tree.iter_sections())
docs: Calculate the total number of segments that are required
      for the dendrogram. There is a vertical line for each segment
      and two horizontal line at each branching point