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.
To run the tests:
$ gradle testFor more detailed info about the Java track see the help page.
It's possible to submit an incomplete solution so you can see how others have completed the exercise.