Create a new Java project called 1410_Recursion. Add a package recursion and a class Recursion. Include the following three static methods described below. However, don't implement them right away. Instead, start by returning the default value followed by a // TODO comment.

1. public static int sumOfDigits(int n) This method returns the sum of all the digits. sumOfDigits(-34) -> 7 sumOfDigits(1038) -> 12
2. public static int countSmiles(char[] letters, int index) This method counts the number of colons followed by a closing parenthesis. countSmiles([:,), ,L,i,f,e, ,i,s, ,g,o,o,d, ,:,)], 0) -> 2 countSmiles([H,a,p,p,y, ,D,a,y, ,:,),:,),:,),!], 0) -> 3 countSmiles([a,:,b,(,c,),:, ,),e], 0) -> 0
3. public static String toUpper(String str) This method separates all characters by a space and changes all lowercase letters to uppercase letters. E.g. "Hi there!" returns "H I T H E R E !" Hint: Class Character (Links to an external site.) includes a method toUpperCase (Links to an external site.)

Create a second source folder called test. It should include a class RecursionTest. That's where you will write the JUnit tests for the three methods above.

• Each of the three methods should have at least eight corresponding JUnit tests.
• Choose test data deliberately to provide thorough testing that covers as many potential problems as possible.

Once you have written the JUnit tests, implement the methods.