# Flatten Array Take a nested list and return a single flattened list with all values except nil/null. The challenge is to write a function that accepts an arbitrarily-deep nested list-like structure and returns a flattened structure without any nil/null values. For Example input: [1,[2,3,null,4],[null],5] output: [1,2,3,4,5] # Running the tests You can run all the tests for an exercise by entering ```sh $ gradle test ``` in your terminal. ## Source Interview Question [https://reference.wolfram.com/language/ref/Flatten.html](https://reference.wolfram.com/language/ref/Flatten.html) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.