docs: public boolean isTileToBeDownloaded(final ITileSource pTileSource, final long pMapTileIndex) {
          final Long expiration = mTileWriter.getExpirationTimestamp(pTileSource, pMapTileIndex);
          if (expiration == null) {
              return true;
          }
          final long now = System.currentTimeMillis();
          return now > expiration;
      }