r - number_section yaml-argument：如何检查，是否手动设置为true

Question

在yamlmarkdown_document2的number_section参数中，默认设置为true. 因为officedown我正在寻找一种方法来检查这一事实，即用户确实手动设置了值并且真的希望获得自动编号的标题。!is.null()不是选项，isTrue()在任何一种情况下都确实如此 - 默认值或手动设置。

---
title: number_section with rdocx_document
subtitle: how to check, if number_section was set manually
output:
   bookdown::markdown_document2:
     base_format: officedown::rdocx_document
     number_section: FALSE
     fig_caption: TRUE
---

# This is the first Headline − should be auto-numbered

... but only, if the user sets `number_section: TRUE`