Method fmt

src/plot_widget.rs:1209–1213

(&self, f: &mut std::fmt::Formatter<'_>)

            })
    }

    fn toggle_visibility(&mut self, id: &ShapeId) {
        let exists = self.series.contains_key(id)
            || self.fills.contains_key(id)
            || self.vlines.contains_key(id)
            || self.hlines.contains_key(id);

        if !exists {