nullable :: [Text] -> IsNullable
nullable s
    | "Maybe"    `elem` s = Nullable ByMaybeAttr
    | "nullable" `elem` s = Nullable ByNullableAttr
    | otherwise = NotNullable
nullable :: [Text] -> IsNullable
nullable s
    | "Maybe"    `elem` s = Nullable ByMaybeAttr
    | "nullable" `elem` s = Nullable ByNullableAttr
    | otherwise = NotNullable
nullable s
    | "Maybe"    `elem` s = Nullable ByMaybeAttr
    | "nullable" `elem` s = Nullable ByNullableAttr
    | otherwise = NotNullable