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: octo_fetcher.rb
    path of file: ./repos/github-changelog-generator/lib/github_changelog_generator
    
    the code of the file until where you have to start completion: # frozen_string_literal: tr
    
    def fetch_github_token
      env_var = @options[:token].presence || ENV["CHANGELOG_GITHUB_TOKEN"]

      Helper.log.warn NO_TOKEN_PROVIDED unless env_var

      env_var
    end