ntioned, this was mainly implemented to allow for the closing of
all IDs that are still open inside a file and to invalidate all existing
R6-classes as well.</p>
<div class="section level4">
<h4 id="opening-and-closing-of-files">Opening and closing of files<a class="anchor" aria-label="anchor" href="#opening-and-closing-of-files"></a>
</h4>
<p>In this context, let us quickly also discuss the special way HDF5
handles files. In HDF5, in principle a file can always only be opened
once. This can lead to problem