This test investigates the possible performance impact of extending JavaScript's native String class by adding methods to the class' prototype.
The test first times the duration for instantiating a String instance many times over, and then calling a method on the instance many times over - in both cases with no extended methods on the String class. Then, a bunch of extended methods are generated and assigned on the String.prototype object. The repeated instantiation and repeated method call tests are then performed again and timed.