code: private static String getNextSerializationFileName() {
          List<Integer> usedIndexes = getUsedIndexes();
  
          int maxUsedIndex;
  
          try {
              maxUsedIndex = Collections.max(usedIndexes);
          } catch (Exception e) {
              maxUsedIndex = -1;
          }
  
          return latestMOTDSerializedFileName.replace("{index}", Integer.toString(maxUsedIndex + 1));
      }
docs: Returns the file name to be used for serializing a new {@code MOTD}
  
  @return The file name to be used for serializing a new {@code MOTD}