public function toCreateSchema()
    {
        $this->validateRequired();

        if (!is_array($this->getAttribute('container'))) {
            throw new AdldapException('Container attribute must be an array');
        }

        // Set the display name if it's not set
        if ($this->getAttribute('display_name') === null) {
            $displayName = $this->getAttribute('firstname').' '.$this->getAttribute('surname');

            $this->setAttribute('display_name', $displayName);
        }

        return $this->getAttributes();
    }