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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 legend(self, title=None, scale='color', text_color=None):
 """Convience method for adding a legend to the figure. Important: This defaults to the color scale that is generated with Line, Area, Stacked Line, etc charts. For bar charts, the scale ref is usually 'y'. Parameters title: string, default None Legend Title scale: string, default 'color' Scale reference for legend text_color: str, default None Title and label color """


        self.legends.append(Legend(title=title, fill=scale, offset=0,
                                   properties=LegendProperties()))
        if text_color:
            color_props = PropertySet(fill=ValueRef(value=text_color))
            self.legends[0].properties.labels = color_props
            self.legends[0].properties.title = color_props
        return self