private static function generateColumns(array $columns, array $unique)
    {
        $definition = '';
        foreach ($columns as $column) {
            $tmp = sprintf("    '%s' => \$this->%s%s,\n",
                $column->name, static::getSchemaType($column), static::other($column, $unique));

            if (null !== $column->enumValues) {
                $tmp = static::replaceEnumColumn($tmp);
            }
            $definition .= $tmp;
        }
        return $definition;
    }