Write a method that returns the middle element of a String[] array.

If there are an odd number of elements in the array, return the element in the middle of the array.

For example:

middleElement(new String[]{"hello", "world", "!"})

Should return:

"world"

If there are an even number of elements in the array, return the second of the two middle elements.

For example:

middleElement(new String[]{"my", "name", "is", "Karel"})

Should return:

"is"

If there is are no elements in the array, return the empty String “”.

For example:

middleElement(new String[]{})

Should return:

""