I'd like to have one master class with the methods derived from many other functions attached to it. So say I have 

```
class MasterObject {
   method1...,
   method2...,
   etc...
}

```

Using ES6, id like to import these functions to assign to the MasterClass as methods. So I have tried something like this:

```
function setUpObj (...fns) {

    class MasterObj {
         constructor (...args) {
              Object.assign(this, args)
         }
    }

    return new MasterObj(fns)
 }

 let master = setUpObj(square, add, divide)

 master.square(1,2) 

```

When I do this, the methods are not actually assigned to the object (I am assuming they are assigned to the this, but not as methods). Clearly I don't understand how prototypical inheritance works, so if you can explain it in terms of ES6 classes that would really help me a lot. 

Relevant: 
<https://gist.github.com/allenwb/53927e46b31564168a1d>
[ES6 Class Multiple inheritance](https://stackoverflow.com/questions/29879267/es6-class-multiple-inheritance)