code: public static <T> boolean addAllIterable(Iterable<? extends T> iterable, Collection<T> targetCollection)
      {
          if (iterable == null)
          {
              throw new NullPointerException();
          }
          if (iterable instanceof Collection<?>)
          {
              return targetCollection.addAll((Collection<T>) iterable);
          }
          int oldSize = targetCollection.size();
          Iterate.forEachWith(iterable, Procedures2.<T>addToCollection(), targetCollection);
          return targetCollection.size() != oldSize;
      }
docs: Add all elements from the source Iterable to the target collection, returns true if any element was added.