### Question:
PropertyUtil { public static String stripPrefix(String value, String prefix) { if (value != null && prefix != null && value.startsWith(prefix)) { return value.substring(prefix.length()); } return value; }  static URI replaceQuery(URI originalURI, Map<String, String> properties); static URI replaceQuery(URI uri, String query); static URI eraseQuery(URI uri); static String createQueryString(Map<String, ? extends Object> options); static Map<String, String> parseQuery(URI uri); static Map<String, String> parseQuery(String queryString); static Map<String, String> filterProperties(Map<String, String> properties, String optionPrefix); static Map<String, String> setProperties(Object target, Map<String, String> properties); static Map<String, Object> setProperties(Object target, Properties properties); static Map<String, String> getProperties(Object object); static Object getProperty(Object object, String name); static boolean setProperty(Object target, String name, Object value); static String stripPrefix(String value, String prefix); static String stripUpto(String value, char c); static String stripBefore(String value, char c);  }### Answer:
@Test public void testStripPrefix() { String value = "prefixed.option"; String result = PropertyUtil.stripPrefix(value, "prefixed."); assertEquals("option", result); }
@Test public void testStripPrefixNullPrefix() { String value = "prefixed.option"; String result = PropertyUtil.stripPrefix(value, null); assertSame(value, result); }
@Test public void testStripPrefixNullValue() { assertNull(PropertyUtil.stripPrefix((String) null, "prefixed.")); }