public void putElements(K key,Set<E> elements){
synchronized (this) {
    removeKey(key);
    if (!elements.isEmpty()) {
      for (      E element : elements) {
        addElement(key,element);
      }
    }
  }
}

public void putElements ( K key , Set < E > elements ) { synchronized ( this ) { removeKey ( key ) ; if ( ! elements . isEmpty ( ) ) { for ( E element : elements ) { addElement ( key , element ) ; } } } }
sets the elements corresponding to a particular key . the existing set for that key ( if it exists ) is cleared .
