pub(crate) trait IntDigits {
    // Required methods
    fn digits(&self) -> &[u64];
    fn digits_mut(&mut self) -> &mut Vec<u64>;
    fn normalize(&mut self);
    fn capacity(&self) -> usize;
    fn len(&self) -> usize;
}pub(crate) trait IntDigits {
    // Required methods
    fn digits(&self) -> &[u64];
    fn digits_mut(&mut self) -> &mut Vec<u64>;
    fn normalize(&mut self);
    fn capacity(&self) -> usize;
    fn len(&self) -> usize;
}