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: option_parser.rb
    path of file: ./repos/ruby/tool/lrama/lib/lrama
    
    the code of the file until where you have to start completion: require 'optparse'

module Lrama
  # Handle opt
    
    def validate_trace(trace)
      list = %w[
        none locations scan parse automaton bitsets
        closure grammar rules resource sets muscles tools
        m4-early m4 skeleton time ielr cex all
      ]
      h = {}

      trace.each do |t|
        if list.include?(t)
          h[t.to_sym] = true
        else
          raise "Invalid trace option \"#{t}\"."
        end
      end