pub fn comment_block(before: &str, prefix: &str, after: &str, s: &str) -> String {
let middle = textwrap::fill(s, 80 - prefix.len())
.lines()
.map(|s| format!("{}{}", prefix, s))
.collect::<Vec<_>>()
.join("\n");
format!("{}\n{}\n{}\n", before, middle, after)
}