MethodPr

private static void printMatrix(List<List<String>> matrix) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < matrix.size(); i++) {
            for (int j = 0; j < matrix.get(i).size(); j++) {
                sb.append(matrix.get(i).get(j)).append(" ");
            }
            String line = sb.toString();
            line = line.substring(0, line.length() - 1);
            System.out.print(line);
            sb.delete(0, sb.length());
            System.out.println();
        }
    }