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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def to_html(self, show_mean=None, sortable=None, colorize=True, *args, **kwargs):
 """Extend Pandas built in `to_html` method for rendering a DataFrame and use it to render a ScoreMatrix."""

        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