expire_fragment (ActionController::Caching::Fragments)

    # File lib/action_controller/caching.rb, line 310
          def expire_fragment(name, options = nil)
            return unless perform_caching

            key = fragment_cache_key(name)

            if key.is_a?(Regexp)
              self.class.benchmark "Expired fragments matching: #{key.source}" do
                fragment_cache_store.delete_matched(key, options)
              end
            else
              self.class.benchmark "Expired fragment: #{key}" do
                fragment_cache_store.delete(key, options)
              end
            end
          end