code: def check_bundler(self):
          
  
          def get_config(name):
              return name if self.config('bundler.' + name) else ''
  
          from pkg_resources import Requirement, resource_filename
          relative_path = os.path.join('PyGitUp', 'check-bundler.rb')
          bundler_script = resource_filename(Requirement.parse('git-up'),
                                             relative_path)
          assert os.path.exists(bundler_script), 'check-bundler.rb doesn\'t ' \
                                                 'exist!'
  
          return_value = subprocess.call(
              ['ruby', bundler_script, get_config('autoinstall'),
               get_config('local'), get_config('rbenv')]
          )
  
          if self.testing:
              assert return_value == 0, 'Errors while executing check-bundler.rb'
docs: Run the bundler check.