In this problem, you will work with the java.util.function. DoubleToIntFunction interface from the standard library.

In the Functions class, provide two methods that yield objects implementing this interface.

Since each of them needs a class, and CodeCheck doesn't let you add arbitrary files, add the classes as non-public classes to Functions.java.

Also, provide an implementation of the map method that, given an array of double values, yields an array of int values that results from applying a DoubleToIntFunction to each value.

The map function would be more interesting with the Function interface that can handle functions with arbitrary parameter and result types, but we didn't cover enough Java yet to do that.