public function prepare($key, $value, $schema = null)
    {
        if (is_null($schema)) {
            $schema = $this->schema($key);
            if (is_null($schema)) {
                return $value;
                // throw new \Exception('Cannot prepare data to set. Schema not found for key ['.$key.'].');
            }
        }
        return $schema->prepare($value);
    }