### Question:
Html { public static String lineBreaksToBrTags(String string) { return string == null ? null : string.replace("\n", "<br/>"); }  static String escapeHtml(String html); static String unEscapeHtml(String html); static String lineBreaksToBrTags(String string); static String brTagsToLineBreaks(String string);  }### Answer:
@Test public void lineBrTagWhenLineBreak() throws Exception { assertEquals("<br/>", Html.lineBreaksToBrTags("\n")); }
@Test public void lineBrTagWhenLineBreakBetweenTwoParagraphs() throws Exception { assertEquals("a<br/>b", Html.lineBreaksToBrTags("a\nb")); }