Function md5_hex 

pub fn md5_hex(data: &[u8]) -> String

The MD5 digest of some bytes, in lower-case hexadecimal: music21’s getMd5, which hashes a string’s UTF-8.

use music21::common::stringtools::md5_hex;

assert_eq!(md5_hex(b"test"), "098f6bcd4621d373cade4e832627b4f6");