code: @Override
    public boolean addAll(Collection<? extends Character> c) {
      ensureCapacity(size + c.size());
      for (char e : c) {
        elements[size++] = e;
      }
      return c.size() > 0;
    }
docs: /*
  (non-Javadoc)
  
  @see java.util.AbstractCollection#addAll(java.util.Collection)