def peek_key(key)
        case key
        when Integer
          key.to_s
        when String
          key[0, PEEK_SIZE].inspect
        when Array
          str = []
          key.each { |k| str << peek_key(k) }
          str.join(':')[0, PEEK_SIZE]
        else
          peek_key(DigestUtils.pack_urlsafe_base64digest(DigestUtils.digest(key)))
        end
      end
def peek_key(key)
        case key
        when Integer
          key.to_s
        when String
          key[0, PEEK_SIZE].inspect
        when Array
          str = []
          key.each { |k| str << peek_key(k) }
          str.join(':')[0, PEEK_SIZE]
        else
          peek_key(DigestUtils.pack_urlsafe_base64digest(DigestUtils.digest(key)))
        end
      end
Internal: Show first 100 characters of cache key for logging purposes.

 Returns a String with a length less than 100 characters.