### Question:
ELConstantsFunctions { public static String replaceAll(String src, String regex, String replacement) { if (src != null && regex != null) { if (replacement == null) { replacement = ""; } return src.replaceAll(regex, replacement); } return src; }  static Object firstNotNull(Object o1, Object o2); static String concat(String s1, String s2); static String replaceAll(String src, String regex, String replacement); static String appendAll(String src, String append, String delimeter); static String trim(String input); static String timestamp(); static String urlEncode(String input); static String toJsonStr(Map<String, String> map); static String toPropertiesStr(Map<String, String> map); static String toConfigurationStr(Map<String, String> map); static final long KB; static final long MB; static final long GB; static final long TB; static final long PB; static final int SUBMIT_MINUTES; static final int SUBMIT_HOURS; static final int SUBMIT_DAYS; }### Answer:
@Test public void testReplaceAll() { assertEquals("aefefd", ELConstantsFunctions.replaceAll("abcbcd", "bc", "ef")); assertEquals("d1 d2 d3", ELConstantsFunctions.replaceAll("d1,d2,d3", ",", " ")); assertEquals("ayyycd", ELConstantsFunctions.replaceAll("abcbcd", "bcb", "yyy")); assertEquals("acd", ELConstantsFunctions.replaceAll("abcbcd", "bcb", "")); assertEquals(null, ELConstantsFunctions.replaceAll(null, "bcb", "yyy")); assertEquals("abcbcd", ELConstantsFunctions.replaceAll("abcbcd", null, "XYZ")); assertEquals("acd", ELConstantsFunctions.replaceAll("abcbcd", "bcb", null)); }