docs: private final void error() throws ParserException {
  	Integer currentState = stateStack.peek();
  	parserErrors.addError(currentState);
  	if (backtrackEnabled && !backtrackStack.isEmpty()) {
  	    trackBack();
  	    return;
  	}
  	if (!backtrackEnabled) {
  	    logger.trace("No valid action available and back tracking is disabled. Aborting near '"
  		    + getTokenStream().getCodeSample(maxPosition) + "'...");
  	} else {
  	    logger.trace("No valid action available and back tracking stack is empty. Aborting near '"
  		    + getTokenStream().getCodeSample(maxPosition) + "'...");
  	}
  	throw new ParserException(
  		"Error! Could not parse the token stream near '" + getTokenStream().getCodeSample(maxPosition) + "'!");
      }