code: public static Matrix random(int M, int N) {
          Matrix A = new Matrix(M, N);
          for (int i = 0; i < M; i++) {
              for (int j = 0; j < N; j++) {
                  A.data[i][j] = Math.random();
              }
          }
          return A;
      }
docs: create and return a random M-by-N matrix with values between 0 and 1