code: def with_bundler(self):
          
  
          def gemfile_exists():
              """
              Check, if a Gemfile exists in the current repo.
              """
              return os.path.exists('Gemfile')
  
          if 'GIT_UP_BUNDLER_CHECK' in os.environ:
              print(colored(
                  '''The GIT_UP_BUNDLER_CHECK environment variable is deprecated.
  You can now tell git-up to check (or not check) for missing
  gems on a per-project basis using git's config system. To
  set it globally, run this command anywhere:
  
  git config --global git-up.bundler.check true
  
  To set it within a project, run this command inside that
  project's directory:
  
  git config git-up.bundler.check true
  
  Replace 'true' with 'false' to disable checking.''', 'yellow'))
  
          if self.settings['bundler.check']:
              return gemfile_exists()
  
          if ('GIT_UP_BUNDLER_CHECK' in os.environ
                  and os.environ['GIT_UP_BUNDLER_CHECK'] == 'true'):
              return gemfile_exists()
  
          return False
docs: Check, if bundler check is requested.
  
          Check, if the user wants us to check for new gems and return True in
          this case.
          :rtype : bool