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: mailbox_exporter.rb
    path of file: ./repos/imap-backup/lib/imap/backup/thunderbird
    
    the code of the file until where you have to start completion: require "thunderbird/local_folder"

r
    
    def run
      if !profile_set_up
        error "The Thunderbird profile '#{profile.title}' " \
              "has not been set up. " \
              "Please set it up before trying to export"
        return false
      end