code: private String parse(final Arguments arguments, String input) {
          final Configuration configuration = arguments.getConfiguration();
  
          final IStandardExpressionParser parser =
                  StandardExpressions.getExpressionParser(configuration);
  
          final IStandardExpression expression =
                  parser.parseExpression(configuration, arguments, input);
  
          return (String) expression.execute(configuration, arguments);
      }
docs: Parse the expression of an value.
  
  @param arguments thymeleaf arguments.
  @param input the expression.
  @return the eavluated valued.