@Test
    public void testSearcha2DMatrix15() throws Exception {
        int[][] matrix = {
                {1}, {2}, {3}, {4}, {5}, {6}, {7},  {9}, {10}, {11}, {12}, {13}, {14}, {15}, {16}, {17}, {18}, {19}
        };
        int[] exists = existElem(matrix);
        for (int i : exists) {
            System.out.println("Estimate num = " + i);
            assert s.searchMatrix(matrix, i);
        }
        int[] nonExists = {8, 20, 21};
        for (int i : nonExists) {
            System.out.println("Estimate num = " + i);
            assert !s.searchMatrix(matrix, i);
        }
    }