The code seems correct, but there is no unit test for the combine function. So, ideally, a test is written as well to ensure the behavior is indeed the same.

Good point, I will do this after the weekend.

Added unittests, how do they look to you?

The tests pass both on the previous implementation and the one the new one.

Please review and if merging, please use fast-forward merge.

Thanks for the review!

I can't merge due to the required checks:

remote: error: GH006: Protected branch update failed for refs/heads/master.
remote: error: 5 of 5 required status checks have not succeeded: 2 expected and 1 pending.
To https://github.com/quaquel/EMAworkbench.git
 ! [remote rejected] master -> master (protected branch hook declined)
error: failed to push some refs to 'https://github.com/quaquel/EMAworkbench.git'

Fast-forward merge from a fork, for future reference:

git remote add EwoutH https://github.com/EwoutH/EMAworkbench.git
git fetch EwoutH performance-2
git checkout master
git merge --ff-only -S EwoutH/performance-2
git remote remove EwoutH

Thanks, with your script, it was easy for me to fix. I could not figure out how to give you the right to bypass checks.

Awesome, thanks for merging!

When coming close to the 2.4.0 release I will do some benchmarks for overhead and general performance improvements compared to 2.3.0. I believe together with #232 we can reduce the overhead by at least 80%, promising a up to 5x performance improvement for really small models.