/**
* Sets message for a specific key, while preserving other keys
*
* @param SourceInterface $source
* @param string $key
* @param string $message
* @param string $level
*/
protected function setMessage(SourceInterface $source, $key, $message, $level = LogLevel::ERROR)
{
$messages = $source->getMessages();
$messages[$key][$level] = $message;
$source->setMessages($messages);
}
