void populateEditForm(Model uiModel, PurchaseRequest purchaseRequest) {
    uiModel.addAttribute("purchaseRequest", purchaseRequest);

    uiModel.addAttribute("proposals", Proposal.findAllProposals());

    uiModel.addAttribute("purchaserequestparts", PurchaseRequestPart.findAllPurchaseRequestParts());
    uiModel.addAttribute("users", User.findAllUsers());
  }