code: public static StringBuilder maybeQuoteIdentifier(String s) {
          final EscapeStringResult escapeString = escapeString(s, '\'');
          final StringBuilder result = escapeString.buffer;
  
          final boolean need_quotes = s.isEmpty() ||
                  escapeString.needQuotes ||
                  KEYWORDS.contains(s) ||
                  !IDENTIFIER_MATCHER.test(s);
  
          if (need_quotes) {
              result.insert(0, '\'');
              result.append('\'');
          }
          return result;
      }
docs: Create an identifier configuration element.
  @param s an identifier
  @return the identifier as a string, which is escaped and quoted if needed.