def METHOD_NAME(self, connection):
    foos = self.tables.foos
    conn = connection
    conn.execute(insert(foos).values(dict(id=1, bar="b", baz="bz")))
    stmt = insert(foos).values([dict(id=1, bar="ab"), dict(id=2, bar="b")])
    stmt = stmt.on_duplicate_key_update(updated_once=None)
    result = conn.execute(stmt)
    # ambiguous
    eq_(result.inserted_primary_key, (None,))
    eq_(
        conn.execute(foos.select().where(foos.c.id == 1)).fetchall(),
        [(1, "b", "bz", None)],
    )