JavaScript/Typescript "this" reference in Classes

Question

I have problems with the this reference in Javascript (I am an old java developer :) ). I have a service class which is using a this reference inside one method:

export class SomeService {

    constructor(private _resource) { }

    loadData(){
        return this._resource.readData();
    }
}

I try to build a base class on top of this kind of services. For this reason I want to use a reference to this method like that:

export class BaseClass {
    constructor(
        public loadFunction: () => any
    ) { }

    call(){
        this.loadFunction();  
    }
    // ....
}

export class MyLoader extends BaseClass {
    constructor() {
        super(
            customerService.loadCustomers
        )
    }
}

The this reference in SomeService will reference the MyLoad instance. I can change the example above and extend the constructor of the Baseclass with an additional parameter of the context and use "apply" like:

export class BaseClass {
    constructor(
        public loadFunction: () => any,
        public loadContext : any
    ) { }

    call(){
        this.loadFunction.apply(this.loadContext)  
    }
    // ....
}

But it feels like repeating myself. Is that the best (only?) way to archive this?