def valid_entry?(key, year)
      datestr = fetched key
      return false unless datestr
      date = Date.parse datestr
      year || Date.today - date < 60
    end
def valid_entry?(key, year)
      datestr = fetched key
      return false unless datestr
      date = Date.parse datestr
      year || Date.today - date < 60
    end
if cached reference is undated, expire it after 60 days
 @param key [String]
 @param year [String]