Write a method that sums all the numbers in the major diagonal in an n * n matrix of double values using the following header:public static double?sumMajorDiagonal(double[][] m)Write a test program that reads a 4-by-4 matrix and displays the sum of all its elements on the major diagonal. Here is a sample run:

Enter a 4-by-4 matrix row by row: 1 2 3 4.0 - Enter 5 6.5 7 8 - Enter 9 10 11 12 -Enter 13 14 15 16 Sum of the elements in the major diagonal is 34.5 JEnter