Method sibling

src/tree/binary/node.rs:89–101

(node: Option<NonNull<Self>>)

    }

    pub fn sibling(node: Option<NonNull<Self>>) -> Option<NonNull<Self>> {
        unsafe {
            node.and_then(|node| {
                node.as_ref().parent.and_then(|parent| {
                    if parent.as_ref().left == Some(node) {
                        parent.as_ref().right
                    } else {
                        parent.as_ref().left
                    }
                })
            })
        }
    }

    pub fn uncle(node: Option<NonNull<Self>>) -> Option<NonNull<Self>> {
        unsafe {