Create a custom set type.

Sometimes it is necessary to define a custom data structure of some type, like a set. In this exercise you will define your own set. How it works internally doesn't matter, as long as it behaves like a set of unique elements.

Go through the setup instructions for JavaScript to install the necessary dependencies:

http://exercism.io/languages/javascript/installation

The provided test suite uses Jasmine. You can install it by opening a terminal window and running the following command:

npm install -g jasmine

Run the test suite from the exercise directory with:

jasmine custom-set.spec.js

In many test suites all but the first test have been marked "pending". Once you get a test passing, activate the next one by changing xit to it.

It's possible to submit an incomplete solution so you can see how others have completed the exercise.