Function row_hash 

pub fn row_hash(
    record: &Value,
    key: &[String],
    columns: Option<&[String]>,
    exclude: &[String],
    norm: &Normalizer,
) -> u128

A 128-bit fingerprint of record’s compared columns: the key columns plus columns (every non-excluded field when columns is None), each canonicalised through norm. Column order does not matter — the fields are hashed in sorted name order.