Hashing an EPM

[cthoyt]

It might be worth having a way to hash an EPM so they can be quickly indexed / compared for equality

def get_hash(self) -> str:
    import hashlib
    from operator import attrgetter

    h = hashlib.md5()
    for record in sorted(self.records, key=attrgetter("prefix")):
        h.update(record.prefix.encode("utf8"))
        h.update(record.uri_prefix.encode("utf8"))
        for s in itt.chain(sorted(record.prefix_synonyms), sorted(record.uri_prefix_synonyms)):
            h.update(s.encode("utf8"))
    return h.hexdigest()