code: public void removeLeadingField(String sourceField, String targetField, String regexString, String length) {
          TransformationStep step = new TransformationStep();
          step.setSourceFields(sourceField);
          step.setTargetField(targetField);
          step.setOperationParameter(TransformationConstants.REMOVELEADING_LENGTH_PARAM, length);
          step.setOperationParameter(TransformationConstants.REGEX_PARAM, regexString);
          step.setOperationName("removeleading");
          steps.add(step);
      }
docs: Adds a remove leading step to the transformation description. The source and the target field need to be of
  String type. Based on the given regular expression string the beginning of the source string will be removed
  until the given maximum length. If the length is 0, the maximum length is ignored.