code: public static void printLongString(Appendable out, CharSequence text)
          throws IOException
      {
          if (text == null)
          {
              out.append("null.string");
          }
          else
          {
              out.append("'''");
              printCodePoints(out, text, EscapeMode.ION_LONG_STRING);
              out.append("'''");
          }
      }
docs: Prints characters as an ASCII-encoded Ion "long string",
  including surrounding triple-quotes.
  If the {@code text} is null, this prints {@code null.string}.
  
  @param out the stream to receive the data.
  @param text the text to print; may be {@code null}.
  
  @throws IOException if the {@link Appendable} throws an exception.
  @throws IllegalArgumentException
  if the text contains invalid UTF-16 surrogates.