code: public void consumeExpectedSymbol(String symbol) {
          if (current().matches(Token.TokenType.SYMBOL, symbol)) {
              consume();
          } else {
              addError(current(), "Unexpected token: '%s'. Expected: '%s'", current().getSource(), symbol);
          }
      }
docs: Consumes the current token, expecting it to be as <tt>SYMBOL</tt> with the given content
  
  @param symbol the expected trigger of the current token