function Person(name, surname) {
	this.name = name;
	this.surname = surname;
}

var myMixin = {
	getFullName: function() { 
		return this.name + " " + this.surname;
	}
};

function augment(destination, source) {
  for (var methodName in source) {
    if (source.hasOwnProperty(methodName)) {
      destination[methodName] = source[methodName];
    }
  }
  return destination; 
}

augment(Person.prototype, myMixin);

var johnSmith = new Person("Jan", "Kowalski");

console.log(johnSmith.getFullName());		// wynik: "Jan Kowalski"
