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: language_exporter.rb
    path of file: ./repos/mushroom-observer/app/models
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

#
#  = Language Locali
    
  def check_export_file_for_duplicates
    once = {}
    twice = {}
    pass = true
    read_export_file_lines.each do |line|
      next unless line =~ /^ *['"]?(\w+)['"]?:/

      if once[Regexp.last_match(1)] && !twice[Regexp.last_match(1)]
        verbose("#{locale} #{Regexp.last_match(1)}: " \
                "tag appears more than once")
        twice[Regexp.last_match(1)] = true
        pass = false
      end
      once[Regexp.last_match(1)] = true
    end