hmm.rs

    pub fn add_scope_processor<F>(&mut self, f: Box<F>)
    where
        F: Fn(&mut Event) + Sync + Send + ?Sized,
        Box<F>: im::shared::Shared<Box<Fn(&mut Event) + Sync + Send>>,
    {
        self.scope_processors = self.scope_processors.push_back(f);
    }

    pub fn add_scope_processor<F>(&mut self, f: F)
    where
        F: Fn(&mut Event) + Sync + Send + ?Sized,
    {
        self.scope_processors = self.scope_processors.push_back(box f);
}