Under some circumstances using the API, the Suffix field is None, and the LongName field does not include the suffix for persons whose name includes a suffix.
If you getAncestors for Swayne-99, whose LongName should be "Samuel Fothergill Swayne II" the LongName correctly includes the suffix and the Suffix field contains "II". If you getAncestors for Swayne-74, his son, the LongName for Swayne-99 is truncated to "Samuel Fothergill Swayne" and the Suffix field is None.