code: def _compare_rows(from_recs, to_recs, keys):
      "Return the set of keys which have changed."
      return set(
          k for k in keys
          if sorted(from_recs[k].items()) != sorted(to_recs[k].items())
      f _compare_rows(from_recs, to_recs, keys):
      "Return the set of keys which have changed."
      return set(
          k for k in keys
          if sorted(from_recs[k].items()) != sorted(to_recs[k].items())
      )
docs: Return the set of keys which have changed.