How to access super function when overriding a function using a function passed as a parameter in Javascript?

Question

I am overriding the functions of different classes by passing an object of functions as a parameter.

var parameter = {function1: function() {...}, function2: function() {...}}

Is it possible to call the original function, as would be done using super() when extending the class, from the overriding function being passed in?

var parameter = {function1: function() {// I want to call the original function1 of whatever class im going to be overriding, then do something else}, function2: function() {...}}

Further context: I am making a custom widget on surveyjs.