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: token.rb
    path of file: ./repos/OpenFarm/app/models
    
    the code of the file until where you have to start completion: class Token
  include Mongoid::Document
  inc
    
  def fully_formed
    if plaintext.present?
      "#{user.email}:#{plaintext}"
    else
      raise OpenfarmErrors::StaleToken, """You attempted to access the
      plaintext version of an access token. Unfortunately, this token has
      been saved and therefore no longer has a viewable plaintext secret.
      You must create a new token and destroy the old one or provide the
      plaintext secret  by other means.""".squish
    end