solution-part-1.js

var Person = function (first, last) {
  this.firstName = first;
  this.lastName = last;
}

Object.defineProperty(Person, 'species', {
  writable: false,
  value: 'human'
});

var woman = new Person('Kate', 'Khowalski');
woman; // Person {firstName: 'Kate', lastName: 'Khowalski', species: 'human'}

/*
 * Try to overwrite species
 */

woman.species = 'fish';
woman.species; // 'human' - We can't change this value.