Message::setFiles

public function setFiles($files): self
{
	$fileIds = [];
	if ($files instanceof FileCollection)
	{
		$this->files = $files;
		foreach ($this->files as $fileItem)
		{
			$fileIds[] = $fileItem->getDiskFileId();
		}
	}
	elseif (is_array($files))
	{
		$fileIds = array_filter(array_map('intval', array_values($files)));
	}

	$this->getParams()->get(Params::FILE_ID)->setValue($fileIds);

	return $this;
}