code: public static <T> boolean addAll(Collection<T> target, Iterable<? extends T> iterable) {
          if (iterable instanceof Collection) {
              return target.addAll((Collection<? extends T>) iterable);
          }
          return Iterators.addAll(target, iterable.iterator());
      }
docs: Add all elements in the iterable to the collection.
  
  @param target
  @param iterable
  @return true if the target was modified, false otherwise