code: public RefToken get(int index) throws IndexOutOfBoundsException {
          if (index < 0 || index >= tokens.length) throw new IndexOutOfBoundsException("Illegal index: " + index);
          return tokens[index];
      }
docs: Retrieves the reference token at the specified index.
  
  @param index The desired reference token index.
  @return The specified instance of {@link RefToken}.
  @throws IndexOutOfBoundsException The specified index is illegal.