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: api_token.rb
    path of file: ./repos/metasploit-framework/lib/msf/core/web_services/authentication/strategies
    
    the code of the file until where you have to start completion: module Msf::WebServices::Authentication
  module Strategies
    class ApiToken < Warden::Strategies::Base
      AUTHORIZATION = 'HTTP_AUT
    
      def auth_from_db(token)
        db_manager = env['msf.db_manager']
        user = db_manager.users(persistence_token: token).first

        validation_data = validate_user(user)
        if validation_data[:valid]
          success!(user)
        else
          throw(:warden, message: validation_data[:message], code: validation_data[:code])
        end