docs: public void instantiateField(String targetField, String targetType, String targetTypeInit, String... sourceFields) {
          TransformationStep step = new TransformationStep();
          step.setSourceFields(sourceFields);
          step.setTargetField(targetField);
          step.setOperationParameter(TransformationConstants.INSTANTIATE_TARGETTYPE_PARAM, targetType);
          if (targetTypeInit != null) {
              step.setOperationParameter(TransformationConstants.INSTANTIATE_INITMETHOD_PARAM, targetTypeInit);
          }
          step.setOperationName("instantiate");
          steps.add(step);
      }