Write a method that uses recursion to count the number of times a specific letter occurs in a string using the following method header: public static int charCount(String str, charch). For example, charCount("Welcome", "e") returns 2. Use a helper method with the following header: public static int charCount(String str, char ch, int high) where high represents an index of the string, to improve the algorithm's performance. Demonstrate the method with a driver program called CharacterCounter, that prompts the user to enter a string (i.e., "This is the string"), and then a character, and then displays the number of occurrences of the character in the string