Set Mouse Action Arcball Controls

Hi, I have a question regarding Arcball Controls. I am trying to set new mouse actions but get an error when calling setMouseAction function with strings as parameter as recommended by the documentation. (Argument of type ‘“ROTATE”’ is not assignable to parameter of type ‘ArcballControlsMouseActionOperations’.)
I also can’t import the ArcballControlsMouseActionOperations enum. I am using three r155. Thanks in advance for any help!

Maybe this is some TS-related issue. I hope some of the TS-gurus will give a hand.

A pure vanilla JavaScript would happily accept a string.