### Question:
Header2004 implements IHeader { public void addEle(IElement e) { this.txt.append("\n" + e.getContent()); }  void addEle(IElement e); void addEle(String str); String getContent(); String getHideHeaderAndFooterFirstPageXml(); boolean getHideHeaderAndFooterFirstPage(); void setHideHeaderAndFooterFirstPage(boolean value); static final String HIDE_HEADER__FOOTER_FIRST_PAGE; }### Answer:
@Test public void testAddEle(){ Header2004 hd = new Header2004(); hd.addEle(Paragraph.with("p1")); assertEquals(2, TestUtils.regexCount(hd.getContent(), "<*w:hdr")); assertEquals(1, TestUtils.regexCount(hd.getContent(), "<w:t>p1</w:t>")); }