code: public Long getUnixTimeMillis() {
          String time = tags.get("c");
          if (time == null)
              return null;
          else
              try {
                  return Long.parseLong(time) * 1000;
              } catch (NumberFormatException e) {
                  return null;
              }
      }
docs: Returns the 'c:' value from the tag block times 1000 to convert to
  millis. Returns null if not present.
  
  @return