def get_text_color(self, obj, selected=False): raise ImproperlyConfigured(_("XYChart requires a definition of " "'get_text_color'"))
def get_label_text(self, obj): raise ImproperlyConfigured(_("XYChart requires a definition of " "'get_label_text'"))
def get_xy_values(self, obj): raise ImproperlyConfigured(_("XYChart requires a definition of " "'get_xy_values'"))
def get_value(self, obj): raise ImproperlyConfigured(_("PieChart requires a definition of " "'get_value'"))