4. Consider the following program segment: public class Ch7_PrExercise 4 { public static void main(String[] args) { int num; double dec; } public static int one (int x, int y) { } public static double two (int x, double a) { int first; double z; } a. Write the definition of method one so that it returns the sum of x and y if x is greater than y; otherwise, it should return x minus 2 times y. b. Write the definition of method two as follows: i. Read a number and store it in z. ii. Update the value of z by adding the value of a to its previous value. iii. Assign the variable first the value returned by method one with the parameters 6 and 8. iv. Update the value of first by adding the value of x to its previous value. V. If the value of z is more than twice the value of first, return z; otherwise, return 2 times first minus z. Write a Java program that tests parts a and b. (Declare additional vari- ables in the method main, if necessary.) C