pub fn next_string_sequence(string: &str) -> String {

    let mut bytes = string.as_bytes().to_vec();

    for (index, char) in string.char_indices().rev() {

        let mut next_char = u32::from(char) + 1;

        if next_char == 0xd800 {

        } else if next_char > u32::from(char::MAX) {

        }

        let mut char_bytes = [0; 6];

        bytes.splice(

            index..,

            char::try_from(next_char)

                .unwrap()

                .encode_utf8(&mut char_bytes)

                .bytes(),

        );

        return String::from_utf8(bytes).unwrap();

}