}
impl fmt::Display for Categories {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let mut s = String::new();
        for category in &self.categories {
            s.push_str(&category.to_string());
        };
        write!(f, "{}", s)
    }

impl fmt::Display for Category {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f,
            "id: {}\nname: {}\nparent_id: {}\nnotes: {:?}\n",
            self.id,
            self.name,
            self.parent_id,
            self.notes,
        )
    }
}

impl fmt::Display for CategorySeries {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let mut s = String::new();
        for (i, series) in self.seriess.iter().enumerate() {
            s.push_str(&i.to_string());
            s.push('\n');
            s.push_str(&series.to_string());
            s.push('\n');
        };
        write!(f, "{}", s)
    }
}

impl fmt::Display for TagItem {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f,
            "name: {}\ngroup_id: {}\nnotes: {:?}\n",
            self.name,
            self.group_id,
            self.notes,
        )
    }
}

}
impl fmt::Display for SeriesTags {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let mut s = String::new();
        for (i, tags) in self.tags.iter().enumerate() {
            s.push_str(&i.to_string());
            s.push('\n');
            s.push_str(&tags.to_string());
            s.push('\n');
        };
        write!(f, "{}", s)
    }

        for tag in &self.tags {

        for (i, tag) in self.tags.iter().enumerate() {
            tags.push_str(&i.to_string());
            tags.push('\n');

impl TagsSeries {
    pub fn series_titles(&self) -> String {
        let mut s = String::new();
        for series in &self.seriess {
            s.push_str(&series.title);
            s.push('\n');
        }
        s
    }
}