Method propose

src/plan/hector.rs:1046–1049

(&mut self, prefixes: &Collection<S, P>)

    }

    fn propose(&mut self, prefixes: &Collection<S, P>) -> Collection<S, (P, V)> {
        let value = self.value.clone();
        prefixes.map(move |prefix| (prefix.clone(), value.clone()))
    }

    fn validate(&mut self, extensions: &Collection<S, (P, V)>) -> Collection<S, (P, V)> {
        let target = self.value.clone();