code: def to_html(self, show_mean=None, sortable=None, colorize=True, *args,
                  **kwargs):
          
          if show_mean is None:
              show_mean = self.show_mean
          if sortable is None:
              sortable = self.sortable
          df = self.copy()
          if show_mean:
              df.insert(0, 'Mean', None)
              df.loc[:, 'Mean'] = ['%.3f' % self[m].mean() for m in self.models]
          html = df.to_html(*args, **kwargs)  # Pandas method
          html, table_id = self.annotate(df, html, show_mean, colorize)
          if sortable:
              self.dynamify(table_id)
          return html
docs: Extend Pandas built in `to_html` method for rendering a DataFrame
          and use it to render a ScoreMatrix.