 or interface in java.util" class="external-link">add</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/HashSet.html#clear()" title="class or interface in java.util" class="external-link">clear</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/HashSet.html#clone()" title="class or interface in java.util" class="external-link">clone</a>, <a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/HashSet.html#contains(j