text: public synchronized boolean containsValue(Object value) {if (value == null) {throw new NullPointerException();}HashtableEntry[] tab = table;int len = tab.length;for (int i = 0; i < len; i++) {for (HashtableEntry e = tab[i]; e != null; e = e.next) {if (value.equals(e.value)) {return true;}}}return false;}