Render the GeoJson/TopoJson and color scale objects.

def render(self, **kwargs):
        """Render the GeoJson/TopoJson and color scale objects."""
        if self.color_scale:
            # ColorMap needs Map as its parent
            assert isinstance(self._parent, Map), ('Choropleth must be added'
                                                   ' to a Map object.')
            self.color_scale._parent = self._parent

        super(Choropleth, self).render(**kwargs)