private void LoadData(DateTime tanggalMulai, DateTime tanggalSelesai)
        {
            using (new StCursor(Cursors.WaitCursor, new TimeSpan(0, 0, 0, 0)))
            {
                _listOfRetur = _bll.GetByTanggal(tanggalMulai, tanggalSelesai);
                GridListControlHelper.Refresh <ReturBeliProduk>(this.gridList, _listOfRetur);
            }

            ResetButton();
        }
        public void GetByTanggalTest()
        {
            var index      = 0;
            var tglMulai   = new DateTime(2017, 1, 1);
            var tglSelesai = new DateTime(2017, 1, 21);

            var oList = _bll.GetByTanggal(tglMulai, tglSelesai);
            var obj   = oList[index];

            // tes retur
            Assert.IsNotNull(obj);
            Assert.AreEqual("2fb82570-d64e-4f2d-bd03-aab5bdf75884", obj.retur_beli_produk_id);
            Assert.AreEqual("27d40236-c8ab-44be-bc47-7a9bbd68c31e", obj.beli_produk_id);
            Assert.AreEqual("af01c916-7976-4518-a563-9d2a1851a912", obj.supplier_id);
            Assert.AreEqual("201701210010", obj.nota);
            Assert.AreEqual(DateTime.Today, obj.tanggal);
            Assert.AreEqual("keterangan", obj.keterangan);
            Assert.AreEqual(160000, obj.total_nota);

            // tes item retur
            Assert.AreEqual(2, obj.item_retur.Count);

            index = 1;
            var itemRetur = obj.item_retur[index];

            Assert.AreEqual("d7e888eb-6f9b-43ef-9a72-212588d2fb38", itemRetur.Produk.produk_id);
            Assert.AreEqual("12345", itemRetur.Produk.kode_produk);
            Assert.AreEqual("susu coklat", itemRetur.Produk.nama_produk);
            Assert.AreEqual(2, itemRetur.jumlah_retur);
            Assert.AreEqual(3500, itemRetur.harga);

            // tes supplier
            var supplier = obj.Supplier;

            Assert.AreEqual("af01c916-7976-4518-a563-9d2a1851a912", supplier.supplier_id);
            Assert.AreEqual("TE Shop", supplier.nama_supplier);
            Assert.AreEqual("Yogyakarta", supplier.alamat);

            // tes beli
            var beli = obj.BeliProduk;

            Assert.AreEqual("27d40236-c8ab-44be-bc47-7a9bbd68c31e", beli.beli_produk_id);
            Assert.AreEqual("201701200045", beli.nota);
        }