AbstractOpenAiCompatibleImageGenerationModel::preparePromptParam( WordPress\AiClient\Providers\OpenAiCompatibleImplementation\list<Message> $messages ): string

133    protected function preparePromptParam(array $messages): string134    {135        if (count($messages) !== 1) {136            throw new InvalidArgumentException('The API requires a single user message as prompt.');137        }138        $message = $messages[0];139        if (!$message->getRole()->isUser()) {140            throw new InvalidArgumentException('The API requires a user message as prompt.');141        }142        $text = null;143        foreach ($message->getParts() as $part) {144            $text = $part->getText();145            if ($text !== null) {146                break;147            }148        }149        if ($text === null) {150            throw new InvalidArgumentException('The API requires a single text message part as prompt.');151        }152        return $text;153    }