code: private static String getVersion() {
      final String defaultVersion = "dev-" + System.currentTimeMillis();
      final String fileName = "bigtable-version.properties";
      final String versionProperty = "bigtable.version";
      try (InputStream stream =
          BigtableVersionInfo.class.getResourceAsStream(fileName)) {
        if (stream == null) {
          LOG.error("Could not load properties file bigtable-version.properties");
          return defaultVersion;
        }
  
        Properties properties = new Properties();
        properties.load(stream);
        String value = properties.getProperty(versionProperty);
        if (value == null) {
          LOG.error("%s not found in %s.", versionProperty, fileName);
        } else if (value.startsWith("$")){
          LOG.info("%s property is not replaced.", versionProperty);
        } else {
          return value;
        }
      } catch (IOException e) {
        LOG.error("Error while trying to get user agent name from %s", e, fileName);
      }
      return defaultVersion;
    }
docs: Gets user agent from bigtable-version.properties. Returns a default dev user agent with current
  timestamp if not found.