sample.js

var a = function(fn1, fn2) {
  var value = 123;
  return {
    fn1: fn1(value),
    fn2: fn2(value)
  }
};

var b = a(function(value){
  return function() {
    value = value + 1;
  }
}, function(value){
  return function() {
    return value;
  }
});

console.log(b)

b.fn1();

console.log(b.fn2());