code: public int addFirst(Iterable<? extends KTypeCursor<? extends KType>> iterable) {
      int size = 0;
      for (KTypeCursor<? extends KType> cursor : iterable) {
        addFirst(cursor.value);
        size++;
      }
      return size;
    }
docs: Inserts all elements from the given iterable to the front of this deque.
  
  @param iterable The iterable to iterate over.
  
  @return Returns the number of elements actually added as a result of this
  call.