code: public String
  getString() throws IOException {
  	Token next = get();
  	if (!next.isString()) {
  		throw exception("expected a string");
  	}
  	return next.value;
  }
docs: Gets the next token from a tokenizer and converts it to a string.
  @return The next token in the stream, as a string.
  @throws TextParseException The input was invalid or not a string.
  @throws IOException An I/O error occurred.