public static String wrapWithMarkdownClassDiv(String html) {
    return new StringBuilder()
        .append("<div class=\"markdown-body\">\n")
        .append(html)
        .append("\n</div>")
        .toString();
  }
@Test
  void testHeader() {
    InterpreterResult r1 = md.interpret("# H1", null);
    assertEquals(wrapWithMarkdownClassDiv("<h1>H1</h1>\n"), r1.message().get(0).getData());

    InterpreterResult r2 = md.interpret("## H2", null);
    assertEquals(wrapWithMarkdownClassDiv("<h2>H2</h2>\n"), r2.message().get(0).getData());

    InterpreterResult r3 = md.interpret("### H3", null);
    assertEquals(wrapWithMarkdownClassDiv("<h3>H3</h3>\n"), r3.message().get(0).getData());

    InterpreterResult r4 = md.interpret("#### H4", null);
    assertEquals(wrapWithMarkdownClassDiv("<h4>H4</h4>\n"), r4.message().get(0).getData());

    InterpreterResult r5 = md.interpret("##### H5", null);
    assertEquals(wrapWithMarkdownClassDiv("<h5>H5</h5>\n"), r5.message().get(0).getData());

    InterpreterResult r6 = md.interpret("###### H6", null);
    assertEquals(wrapWithMarkdownClassDiv("<h6>H6</h6>\n"), r6.message().get(0).getData());

    InterpreterResult r7 = md.interpret("Alt-H1\n" + "======", null);
    assertEquals(wrapWithMarkdownClassDiv("<h1>Alt-H1</h1>\n"), r7.message().get(0).getData());

    InterpreterResult r8 = md.interpret("Alt-H2\n" + "------", null);
    assertEquals(wrapWithMarkdownClassDiv("<h2>Alt-H2</h2>\n"), r8.message().get(0).getData());
  }