Require file nodeJs

I have a file. a.js

class A{
  constructor(name){
        this.name = name;
    }

  displayName(){
    console.log(this.name);
  }
}
module.exports = Render;

Another file common.js

const A = require('./a');
exports.A;

Another file b.js

const common  = require('./common');
var a = new common.A('My name is khan and I am not a terrorist');
a.displayName();

I am getting an error A is not a constructor. Please help, how can get it done. Please forgive my silly mistakes, I am newbie.

via Imran