code: private static String escapeKeyword(String symbol, EscapeStrategy strategy) {
      if (tsKeywords.contains(symbol)) {
        if (strategy.equals(EscapeStrategy.MANGLE)) {
          return symbol + "$";
        } else {
          return "\"" + symbol + "\"";
        }
      } else {
        return symbol;
      }
    }
docs: Returns the escaped Pegasus symbol for use in Typescript source code.
  
  Pegasus symbols must be of the form [A-Za-z_], so this routine simply checks if the
  symbol collides with a typescript keyword, and if so, escapes it.
  
  @param symbol the symbol to escape
  @param strategy which strategy to use in escaping
  
  @return the escaped Pegasus symbol.