### Question:
WikiTextUtils { public static String subsup(String markup) { return markup.replaceAll("[{<]sub[}>](.+?)[{<]/sub[}>]", "_$1") .replaceAll("[{<]sup[}>](.+?)[{<]/sup[}>]", "^$1"); }  static List<MathTag> findMathTags(String text); static String replaceAllFormulas(String text, List<MathTag> mathTags); static String renderAllFormulae(String text); static String subsup(String markup); static String extractPlainText(String wikiMarkup); static String deLinkify(Word word, ParsedWikiDocument doc); static final Pattern MATH_TAG_PATTERN; }### Answer:
@Test public void extractPlainText_subsup() { String input = "V = V<sub>0</sub>. E < V<sup>24</sup>"; String actual = WikiTextUtils.subsup(input); String expected = "V = V_0. E < V^24"; assertEquals(expected, actual); }