Function through_line 

pub fn through_line(
    tr: &Translator,
    through: Option<&Through>,
    emergency_at: i64,
    now: i64,
    when: &dyn Fn(i64) -> String,
) -> String

“Let every call through” in words: “Every call rings until 15:30.”, “… until you turn it off.”, or after an emergency call, “Every call rings until tomorrow at 09:31: you called an emergency number.”; “” otherwise. through and emergency_at in ms; when words an instant (ms).