Count the frequency of letters in texts using parallel computation.

Parallelism is about doing things in parallel that can also be done sequentially. A common example is counting the frequency of letters. Create a function that returns the total frequency of each letter in a list of texts and that employs parallelism.

Single-threaded (non-concurrent) solutions can pass all tests but the last. Your solution will be tested for concurrency by submitting it as a Runnable to an ExecutorService. Your solution must leverage multiple Threads to pass the final test.

Java documentation on parallel streams may provide some help.

As a stretch goal, consider if your implementation will work for characters with diacritics or accents. For example, such solutions should not consider e and ë the same character. An example text for this case is Wilhelmus, the Dutch national anthem.

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

https://exercism.io/tracks/java/installation

You can run all the tests for an exercise by entering the following in your terminal:

$ gradle test

Use gradlew.bat if you're on Windows

In the test suites all tests but the first have been skipped.

Once you get a test passing, you can enable the next one by removing the @Ignore("Remove to run test") annotation.

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