Use class from a different file

Please refer to the link in the comment below and it worked.
Class Editor File

module.exports=class Cat{
// the middle of a class
}

User side files

const Cat=require(./filename);
let cat = new Cat;

For ES6, the class definition is as follows:

export default class Cat{
}

I think this is fine for the user.

import Cat from 'Cat';

When you do the above, you will need to transfer it to the babel.I added m(__)m