Method delete

src/tree/binary/rb2.rs:162–173

(&mut self, key: &K)

    }

    fn delete(&mut self, key: &K) {
        if self.contains(key) {
            let mut root = NodeQuery::new(self.root);
            if !root.left().is_red() && !root.right().is_red() {
                root.set_color(Color::Red);
            }
            root.node = delete(root.node, key);
            root.set_color(Color::Black);
            self.root = root.node;
            self.set_size(self.size() - 1);
        }
    }

    fn contains(&self, key: &K) -> bool {
        unsafe { bst::find(self.root, key).is_some() }