code: def hide_zeroes(self):
          '''
          Sometimes it makes sense to hide the labels for subsets whose size is zero.
          This utility method does this.
          '''
          for v in self.subset_labels:
              if v is not None and v.get_text() == '0':
                  v.set_visible(Falsef hide_zeroes(self):
          '''
          Sometimes it makes sense to hide the labels for subsets whose size is zero.
          This utility method does this.
          '''
          for v in self.subset_labels:
              if v is not None and v.get_text() == '0':
                  v.set_visible(False)
docs: Sometimes it makes sense to hide the labels for subsets whose size is zero.
          This utility method does this.