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: options.rb
    path of file: ./repos/slop/lib/slop
    
    the code of the file until where you have to start completion: # frozen-string-literal: tr
    
    def add_option(option)
      options.each do |o|
        flags = o.flags & option.flags

        # Raise an error if we found an existing option with the same
        # flags. I can't immediately see a use case for this..
        if flags.any?
          raise ArgumentError, "duplicate flags: #{flags}"
        end
      end