Function presence 

pub fn presence<'a>(here: impl IntoIterator<Item = (&'a str, i64)>) -> Value

The roster presence() produces: actor to how many connections that actor holds.

Built here beside the other three because it is the same kind of value — something the host hands a pure program — and because the shape has to be one definition. A page reads it with map_len, map_keys and map_contains, and a second constructor spelling the pairs differently would be a page that renders one way under beck test and another under beck run.