Write a method named `delta`

that accepts an array of integers as a parameter and returns a new array formed by inserting between each pair of values the difference between those values. For example, given this array:

int[] numbers = {3, 8, 15};

The call of `delta(numbers)`

should return the following array:

{3, 5, 8, 7, 15}

In this example, 5 is inserted between 3 and 8 because (8 - 3) is 5, and 7 is inserted between 8 and 15 because (15 - 8) is 7. The difference should always be computed as the second value minus the first, so you can get negative values. For example, given the following array:

int[] numbers2 = {3, 8, 2, 5, 1, 9};

The call of `delta(numbers2)`

should return the array:

{3, 5, 8, -6, 2, 3, 5, -4, 1, 8, 9}

You may assume that the array passed is not `null`

. You may assume that the array contains at least one element.