I mean, when specifying function type, you can&#x27;t specify type of `this` that the function expects to be run with. And `call()` expects thisArg:any, ...args:any[] for all functions regardless of their declared parameter types and expected type of `this`.<p>I&#x27;m talking about the usual js `this`, the covertly passed parameter, not typescript `this`, type of own class.<p>Funny they focused so much on classes that they reached 1.8 without so much as touching js most unique feature, flexible `this`.