pub trait Indentable<T> {
    fn indent(&self, spaces: T) -> String;
}

impl Indentable<usize> for &str {
    fn indent(&self, spaces: usize) -> String {
        let indent_str = " ".repeat(spaces);
        self.lines()
            .map(|line| format!("{}{}", indent_str, line))
            .collect::<Vec<String>>()
            .join("\n")
    }
}

impl Indentable<Option<usize>> for String {
    fn indent(&self, spaces: Option<usize>) -> String {
        self.as_str().indent(spaces.unwrap_or(0))
    }
}

impl Indentable<usize> for String {
    fn indent(&self, spaces: usize) -> String {
        self.as_str().indent(spaces)
    }
}

impl Indentable<Option<usize>> for &str {
    fn indent(&self, spaces: Option<usize>) -> String {
        self.indent(spaces.unwrap_or(0))
    }
}