in src/hashes.rs [143:151]
fn test_hash_chain() {
use blake3::Hasher as Blake3;
let hash_chain_output = hash_chain::<Blake3>(b"01234567890123456789012345678901", 3);
assert_eq!(
hex::encode(hash_chain_output),
"9dce6dd3c7e70a6e5052fe1626b97d5ff50f59764513950df43faf76f15efc5c"
);
}