Function kinds_by_name 

pub fn kinds_by_name<'a>(
    agents: impl IntoIterator<Item = (&'a str, &'a str)>,
    kind_of_block: impl Fn(&str) -> Option<&'static str>,
) -> BTreeMap<String, &'static str>

Each agent’s kind by name, from its block. An agent whose block can’t be read is left out (a peer then shows no tag rather than a guess).