fn remove_all(&mut self) {
        self.items.clear();
        self.n = 0;
        self.r = rand::thread_rng();
    }
// remove_all removes all weighted items.
remove_all removes all weighted items.
remove_all removes all weighted items .
fn remove_all(&mut self) {
        self.items.clear();
        self.n = 0;
        self.r = rand::thread_rng();
    }
fn remove_all ( & mut self ) { self . items . clear ( ) ; self . n = 0 ; self . r = rand :: thread_rng ( ) ; }
remove_all removes all weighted items.
remove_all removes all weighted items .
&mut self
&mut self