code: public void valueField(String targetField, String value) {
          TransformationStep step = new TransformationStep();
          step.setTargetField(targetField);
          step.setOperationParameter(TransformationConstants.VALUE_PARAM, value);
          step.setOperationName("value");
          steps.add(step);
      }
docs: Adds a value step to the transformation description. The given value is written to the target field.