var Person = {
  full_name: function() {
    return this.first_name + " " + this.last_name;
  }
}

var daniel = Object.create(Person, {
  first_name: {
    value: 'Daniel'
  },
  last_name: {
    value: 'Wagener'
  },
});
console.log(daniel.full_name()); //Daniel Wagener