code: protected void setDetailForm(AbstractForm detailForm) {
  		if (this.detailForm != null) {
  			validationResultsModel.remove(this.detailForm.getFormModel()
  					.getValidationResults());
  		}
  
  		this.detailForm = detailForm;
  
  		if (this.detailForm != null) {
  			validationResultsModel.add(this.detailForm.getFormModel()
  					.getValidationResults());
  		}
  	}
docs: Set the form that will handle one detail item.