fix: tds test case
diff --git a/erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py b/erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py
index a0b0cbb..ef77674 100644
--- a/erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py
+++ b/erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py
@@ -7,6 +7,7 @@
 import unittest
 from frappe.utils import today
 from erpnext.accounts.utils import get_fiscal_year
+from erpnext.buying.doctype.supplier.test_supplier import create_supplier
 
 test_dependencies = ["Supplier Group"]
 
@@ -103,17 +104,20 @@
 
 	def test_single_threshold_tds_with_previous_vouchers_and_no_tds(self):
 		invoices = []
-		frappe.db.set_value("Supplier", "Test TDS Supplier2", "tax_withholding_category", "Single Threshold TDS")
-		pi = create_purchase_invoice(supplier="Test TDS Supplier2")
+		doc = create_supplier(supplier_name = "Test TDS Supplier ABC",
+			tax_withholding_category="Single Threshold TDS")
+		supplier = doc.name
+
+		pi = create_purchase_invoice(supplier=supplier)
 		pi.submit()
 		invoices.append(pi)
 
 		# TDS not applied
-		pi = create_purchase_invoice(supplier="Test TDS Supplier2", do_not_apply_tds=True)
+		pi = create_purchase_invoice(supplier=supplier, do_not_apply_tds=True)
 		pi.submit()
 		invoices.append(pi)
 
-		pi = create_purchase_invoice(supplier="Test TDS Supplier2")
+		pi = create_purchase_invoice(supplier=supplier)
 		pi.submit()
 		invoices.append(pi)
 
diff --git a/erpnext/buying/doctype/supplier/test_supplier.py b/erpnext/buying/doctype/supplier/test_supplier.py
index a377ec9..f9c8d35 100644
--- a/erpnext/buying/doctype/supplier/test_supplier.py
+++ b/erpnext/buying/doctype/supplier/test_supplier.py
@@ -120,3 +120,20 @@
 
         # Rollback
         address.delete()
+
+def create_supplier(**args):
+    args = frappe._dict(args)
+
+    try:
+        doc = frappe.get_doc({
+            "doctype": "Supplier",
+            "supplier_name": args.supplier_name,
+            "supplier_group": args.supplier_group or "Services",
+            "supplier_type": args.supplier_type or "Company",
+            "tax_withholding_category": args.tax_withholding_category
+        }).insert()
+
+        return doc
+
+    except frappe.DuplicateEntryError:
+        return frappe.get_doc("Supplier", args.supplier_name)
\ No newline at end of file