Method insert

src/structures/tree.rs:27–40

(&mut self, key: K, value: V)

    }

    pub fn insert(&mut self, key: K, value: V) -> Result<(), io::Error> {
        let mut root = std::mem::replace(&mut self.root, Box::new(Node::new_leaf()));
        if self.is_node_full(&root)? {
            let mut new_root = Node::new_internal();
            let (median, sibling) = root.split()?;
            new_root.keys.push(median);
            new_root.children.push(root);
            new_root.children.push(Box::new(sibling));
            root = Box::new(new_root);
        }
        self.insert_non_full(&mut *root, key, value)?;
        self.root = root;
        Ok(())
    }

    fn insert_non_full(
        &mut self,