10,001st prime

From Project Euler Problem 7

By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.

What is the 10,001st prime number?

Write a class in challenge_7.js named "PrimeFinder" that accepts a single argument n,
where n is the nth prime number to find.
Write an instance method named "getPrimeNumber" that returns the nth prime number.

There are 0 tests, write one test to show the 10,001st prime number.
Write a test case that checks that the object instance method "getPrimeNumber" exists and is a member of the object instance.
Write another test case that checks that "getPrimeNumber" is not a member of the "class" called "PrimeFinder".

(you'll need jasmine-node) npm install jasmine-node -g

run automated tests by running jasmine-node --autotest .