NEW: update copyright year

LICENSE

@@ -1,2 +1,2 @@
-YEAR: 2019, 2020, 2021, 2022
+YEAR: 2019, 2020, 2021, 2022, 2023, 2024
 COPYRIGHT HOLDER: Tim Schäfer

README.md

@@ -20,6 +20,9 @@ install.packages("pkgfilecache")
 
 When package authors want to ship data for their package, they will quickly hit the package size limit on CRAN (which is 5 MB as of September 2019). The solution is to host the data elsewhere and download it on demand when the user requests it, then store it for future use. This is what pkgfilecache allows you to do. You can put your files onto a web server of your choice, take the MD5 sums, and have pkgfilecache download them locally. Files are automatically compared with the local package cache direcory, and only missing files or files with incorrect MD5 checksums will be downloaded. Users can then access the data in a convenient way, similar to accessing files shipped in `inst/extdata` via `system.file`. They can also erase the data if it is no longer needed.
 
+The intended way of using pkgfilecache is to **not** call the download function in your package code, but have it as part of your API that the user can decide to call *if* they want to download the optional data. However, you are of course free to call the download function in your *unit test code*, which will only be run by developers or continuous integration systems.
+
+
 ## How it works
 
 You specify a list of optional data files, and package users can download them with a single command from within GNU R. For each file, you provide: