Server error when Woocommerce disabled

Lat night a client’s website was down for a while, searching through the logs I noticed the follwong:
[03-Apr-2019 21:47:57 UTC] PHP Fatal error: Call to undefined function is_cart() in (...)/wp-content/plugins/klarna-checkout-for-woocommerce/klarna-checkout-for-woocommerce.php on line 298

Turns out Woocommerce was disabled but Klarna was not, and it was calling a Woocommerce function which led to a 500 server error until the plugin as disabled by moving it out of the plugin directory.

Is there something you can do to check for the presence/activity of Woocommerce?

Let me know if you need more info.

Greets