docs: public static ImmutableList<String> splitToLowercaseTerms(String identifierName) {
      if (ONLY_UNDERSCORES.matcher(identifierName).matches()) {
        // Degenerate case of names which contain only underscore
        return ImmutableList.of(identifierName);
      }
      return Arrays.stream(TERM_SPLITTER.split(identifierName))
          .map(String::toLowerCase)
          .collect(toImmutableList());
    }