Function truncate 

pub fn truncate(s: &str, max_bytes: usize) -> &str

Safely truncates a string to a UTF-8-safe prefix sized for truncate_owned.

The returned prefix is at most max_bytes - 3 bytes when truncation is needed, reserving space for the ellipsis that truncate_owned appends.

Use truncate_owned if you need the truncated string with an appended ellipsis (...).

Examples

use rskit_util::strings::truncate;
assert_eq!(truncate("hello world", 8), "hello");
assert_eq!(truncate("hello", 10), "hello");
assert_eq!(truncate("🦀🦀🦀🦀", 8), "🦀");