Function check 

pub fn check(
    due: &Due,
    posted: &Posted,
    extra: &Extra,
    choices: &Choices,
    words: &Words,
    region: Option<&Region>,
) -> Checked

Whether the notification found now by its name is still the one a request answered: the same app and name (notice), and the same conversation as the line answered, read as when the line was made (appnotes::classify): the same shape (a group or not, a group’s title), then its key; else, for a line without one, the same sender’s number, else name; a line that names none of these never passes. What the shade’s own Reply guarantees, and more: the Reply under a notification is that conversation’s (apps make one per conversation, as Android tells them), and an app that reuses one notification for another conversation is caught.