You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: radio_set.rb
    path of file: ./repos/watir/lib/watir
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Watir
  class RadioSet
    extend Forwardable
    include Exception
    include Enumerable
    
    def radio(opt = {})
      if !name.empty? && (!opt[:name] || opt[:name] == name)
        frame.radio(opt.merge(name: name))
      elsif name.empty?
        source
      else
        raise UnknownObjectException, "#{opt[:name]} does not match name of RadioSet: #{name}"
      end
    end