def METHOD_NAME(self):
    m1 = MetaData()
    m2 = MetaData()
    Table(
        "user",
        m1,
        Column("id", Integer, sa.Identity(start=2, on_null=True)),
        Column("other", sa.Text),
    )
    Table(
        "user",
        m2,
        Column("id", Integer, sa.Identity(start=2, on_null=False)),
        Column("other", sa.Text),
    )
    diffs = self._fixture(m1, m2)
    if not config.requirements.supports_identity_on_null.enabled:
        eq_(diffs, [])
    else:
        eq_(len(diffs[0]), 1)
        diffs = diffs[0][0]
        eq_(diffs[0], "modify_default")
        eq_(diffs[2], "user")
        eq_(diffs[3], "id")
        old = diffs[5]
        new = diffs[6]
        is_true(isinstance(old, sa.Identity))
        is_true(isinstance(new, sa.Identity))