Function content_hash 

pub fn content_hash(bytes: &[u8]) -> ContentHash

The ContentHash of bytes.

use rig_core::tool::content_hash;

assert_eq!(
    content_hash(b"").0,
    "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
);