code: public static <T> boolean removeAll(Collection<T> collection, Iterable<? extends T> elements) {
  		return Iterables.removeAll(collection, newHashSet(elements));
  	}
docs: Removes all of the specified elements from the specified collection.
  
  @param collection
  the collection from which the {@code elements} are to be removed. May not be <code>null</code>.
  @param elements
  the elements to remove from the {@code collection}. May not be <code>null</code> but may contain
  <code>null</code> entries if the {@code collection} allows that.
  @return <code>true</code> if the collection changed as a result of the call
  @since 2.4