code: private Integer getSubStringParameter(Map<String, String> parameters, String parameterName, Integer defaultValue)
          throws TransformationOperationException {
          String parameter = parameters.get(parameterName);
          if (parameter == null) {
              getLogger().debug("The {} parameter is not set, so the default value {} is taken.", parameterName,
                  defaultValue);
              return defaultValue;
          }
          try {
              return Integer.parseInt(parameter);
          } catch (NumberFormatException e) {
              throw new TransformationOperationException("The " + parameterName + " parameter is not a number");
          }
      }
docs: Returns the substring parameter with the given parameter or the given default value if the parameter name is not
  set.