code: public static void e(com.couchbase.lite.LogDomain domain, String formatString, Throwable tr, Object... args) {
          String msg;
          try {
              msg = String.format(formatString, args);
              msg = String.format("%s (%s)", msg, tr.toString());
          }
          catch (Exception e) {
              msg = String.format(Locale.ENGLISH, "Unable to format log: %s (%s)", formatString, e.toString());
          }
          sendToLoggers(com.couchbase.lite.LogLevel.ERROR, domain, msg);
      }
docs: Send a ERROR message and log the exception.
  
  @param domain       The log domain.
  @param formatString The string you would like logged plus format specifiers.
  @param tr           An exception to log
  @param args         Variable number of Object args to be used as params to formatString.