diff --git a/dbldatagen/datasets/multi_table_sales_order_provider.py b/dbldatagen/datasets/multi_table_sales_order_provider.py
index 8c8f2d0e..7b855df6 100644
--- a/dbldatagen/datasets/multi_table_sales_order_provider.py
+++ b/dbldatagen/datasets/multi_table_sales_order_provider.py
@@ -245,7 +245,7 @@ def getBaseOrderLineItems(self, sparkSession, *, rows, partitions, numOrders, nu
         base_order_line_items_data_spec = (
             dg.DataGenerator(sparkSession, rows=rows, partitions=partitions)
             .withColumn("order_line_item_id", "integer", minValue=self.ORDER_LINE_ITEM_MIN_VALUE,
-                        uniqueValues=numOrders*lineItemsPerOrder)
+                        uniqueValues=numOrders * lineItemsPerOrder)
             .withColumn("order_id", "integer", minValue=self.ORDER_MIN_VALUE, maxValue=self.ORDER_MIN_VALUE + numOrders,
                         uniqueValues=numOrders, random=True)
             .withColumn("catalog_item_id", "integer", minValue=self.CATALOG_ITEM_MIN_VALUE,
@@ -359,8 +359,9 @@ def getTableGenerator(self, sparkSession, *, tableName=None, rows=-1, partitions
         dummyValues = options.get("dummyValues", 0)
 
         # Get table generation specs for the base tables:
+        spec = None
         if tableName == "customers":
-            return self.getCustomers(
+            spec = self.getCustomers(
                 sparkSession,
                 rows=rows,
                 partitions=partitions,
@@ -368,7 +369,7 @@ def getTableGenerator(self, sparkSession, *, tableName=None, rows=-1, partitions
                 dummyValues=dummyValues
             )
         elif tableName == "carriers":
-            return self.getCarriers(
+            spec = self.getCarriers(
                 sparkSession,
                 rows=rows,
                 partitions=partitions,
@@ -376,7 +377,7 @@ def getTableGenerator(self, sparkSession, *, tableName=None, rows=-1, partitions
                 dummyValues=dummyValues
             )
         elif tableName == "catalog_items":
-            return self.getCatalogItems(
+            spec = self.getCatalogItems(
                 sparkSession,
                 rows=rows,
                 partitions=partitions,
@@ -384,7 +385,7 @@ def getTableGenerator(self, sparkSession, *, tableName=None, rows=-1, partitions
                 dummyValues=dummyValues
             )
         elif tableName == "base_orders":
-            return self.getBaseOrders(
+            spec = self.getBaseOrders(
                 sparkSession,
                 rows=rows,
                 partitions=partitions,
@@ -395,7 +396,7 @@ def getTableGenerator(self, sparkSession, *, tableName=None, rows=-1, partitions
                 dummyValues=dummyValues
             )
         elif tableName == "base_order_line_items":
-            return self.getBaseOrderLineItems(
+            spec = self.getBaseOrderLineItems(
                 sparkSession,
                 rows=rows,
                 partitions=partitions,
@@ -405,7 +406,7 @@ def getTableGenerator(self, sparkSession, *, tableName=None, rows=-1, partitions
                 dummyValues=dummyValues
             )
         elif tableName == "base_order_shipments":
-            return self.getBaseOrderShipments(
+            spec = self.getBaseOrderShipments(
                 sparkSession,
                 rows=rows,
                 partitions=partitions,
@@ -414,13 +415,15 @@ def getTableGenerator(self, sparkSession, *, tableName=None, rows=-1, partitions
                 dummyValues=dummyValues
             )
         elif tableName == "base_invoices":
-            return self.getBaseInvoices(
+            spec = self.getBaseInvoices(
                 sparkSession,
                 rows=rows,
                 partitions=partitions,
                 numOrders=numOrders,
                 dummyValues=dummyValues
             )
+        if spec is not None:
+            return spec
         raise ValueError("tableName must be 'customers', 'carriers', 'catalog_items', 'base_orders',"
                          "'base_order_line_items', 'base_order_shipments', 'base_invoices'")
 
@@ -548,8 +551,7 @@ def getAssociatedDataset(self, sparkSession, *, tableName=None, rows=-1, partiti
                             "a.units as units")
                 .selectExpr("order_id", "order_line_item_id", "unit_price * units as total_price")
                 .groupBy("order_id")
-                .agg(F.count("order_line_item_id").alias("num_line_items"),
-                     F.sum("total_price").alias("order_total"))
+                .agg(F.count("order_line_item_id").alias("num_line_items"),F.sum("total_price").alias("order_total"))
             )
             return (
                dfBaseInvoices.alias("a")
diff --git a/tests/test_standard_dataset_providers.py b/tests/test_standard_dataset_providers.py
index 009e98fb..9cce393d 100644
--- a/tests/test_standard_dataset_providers.py
+++ b/tests/test_standard_dataset_providers.py
@@ -1,7 +1,7 @@
-import pytest
 from datetime import date
-import dbldatagen as dg
 from contextlib import nullcontext as does_not_raise
+import pytest
+import dbldatagen as dg
 
 spark = dg.SparkSingleton.getLocalInstance("unit tests")