/// Returns the floor division of `a` by `b`.
/// This is equivalent to `a.div_euclid(b)` in Rust.
///
/// # Panics
/// Panics if `b` is zero.
/// Returns the modulus after floor division of `a` by `b`.
/// This is equivalent to `a.rem_euclid(b)` in Rust.
///
/// # Panics
/// Panics if `b` is zero.