Received: 21 September 2021
Accepted: 15 October 2021
First Online: 21 October 2021
: The author declares that he has no conflict of interest in this study.
: This study complies with the ethical standards of this journal, with respect to transparency, honesty and original research. This study is "Letter to the Editor" and no patients are involved. Therefore, ethical approval is not necessary.
: There are no new data from humans and animals for discussion in this article.
: As no patients were included in this study, informed consent was not necessary.