code: protected Integer parseIntString(String string, boolean abortOnError, int def)
          throws TransformationOperationException {
          Integer integer = def;
          if (string == null) {
              logger.debug("Given string is empty so the default value is taken.");
          }
          try {
              integer = Integer.parseInt(string);
          } catch (NumberFormatException e) {
              StringBuilder builder = new StringBuilder();
              builder.append("The string ").append(string).append(" is not a number. ");
              if (abortOnError) {
                  builder.append("The step will be skipped.");
              } else {
                  builder.append(def).append(" will be taken instead.");
              }
  
              logger.warn(builder.toString());
              if (abortOnError) {
                  throw new TransformationOperationException(builder.toString());
              }
          }
          return integer;
      }
docs: Parses a string to an integer object. AbortOnError defines if the function should throw an exception if an error
  occurs during the parsing. If it doesn't abort, the given default value is given back as result on error.