public interface IMatrixMultiple {     public int[][] mmltiple(int[][]a ,int [][]b); } ?public class MatrixMultiple implements IMatrixMultiple {     @Override     public int[][] mmltiple(int[][] a, int[][] b) {         int [][] result = new int[a.length][b[0].length];         for (int i = 0; i<a.length; i++) {             for (int j = 0; j<b[0].length; j++) {                 for (int k = 0; k<a[0].length; k++) {                     result[i][j]= result[i][j]+a[i][k]*b[k][j];                 }             }         }         return result;     } }