Function defer 

pub fn defer(
    root: &Path,
    feature: Option<&str>,
    task: &str,
    revoke: bool,
    via: Via,
    state: &Path,
) -> CommandResult

Records (or, with revoke, removes) a person’s decision that task’s acceptance moves to its story’s checkpoint. Refused for a task of no story, a task that names its scenarios, and the checkpoint itself — nothing later would judge them.