Function host_in_set 

pub fn host_in_set(host_literal: &str, set: &[&str]) -> bool

Whether an endpoint HOST literal is in set (case-insensitive; a subdomain of a listed host counts). Strips a :port suffix first via host_part. The shared membership test for TELEMETRY_HOSTS and the config-declared partner set (mirrors candor-java’s Literals.hostInSet).