old_contents: """
  Tests for the MWS.Inventory API class.
  """
  import unittest
  import datetime
  import mws
  from .utils import CommonRequestTestTools
  
  
  class InventoryTestCase(unittest.TestCase, CommonRequestTestTools):
      """
      Test cases for Inventory.
      """
      def setUp(self):
          self.api = mws.Inventory(
              self.CREDENTIAL_ACCESS,
              self.CREDENTIAL_SECRET,
              self.CREDENTIAL_ACCOUNT,
              auth_token=self.CREDENTIAL_TOKEN
          )
          self.api._test_request_params = True
  
      def test_list_inventory_supply(self):
          """
          ListInventorySupply operation
          """
          now = datetime.datetime.utcnow()
          now_timestamp = now.isoformat()
          skus = ['thing1', 'thing2']
          response_group = 'Detailed'
          params = self.api.list_inventory_supply(skus, now, response_group=response_group)
          self.assert_common_params(params)
          assert params['Action'] == 'ListInventorySupply'
          assert params['QueryStartDateTime'] == now_timestamp
          assert params['ResponseGroup'] == 'Detailed'
          assert params['SellerSkus.member.1'] == 'thing1'
          assert params['SellerSkus.member.2'] == 'thing2'
  
      def test_list_inventory_supply_by_next_token(self):
          """
          ListInventorySupplyByNextToken operation
          """
          next_token = 'token_foobar'
          params = self.api.list_inventory_supply(next_token=next_token)
          self.assert_common_params(params)
          assert params['Action'] == 'ListInventorySupplyByNextToken'
          assert params['NextToken'] == next_token
  
      def test_list_inventory_supply_by_next_token_alias(self):
          """
          ListInventorySupplyByNextToken operation by way of the alias method
          list_inventory_supply_by_next_token
          """
          next_token = 'token_foobar'
          params = self.api.list_inventory_supply_by_next_token(next_token)
          self.assert_common_params(params)
          assert params['Action'] == 'ListInventorySupplyByNextToken'
          assert params['NextToken'] == next_token
  
new_contents: """
  Tests for the MWS.Inventory API class.
  """
  import unittest
  import datetime
  import mws
  from .utils import CommonRequestTestTools
  
  
  class InventoryTestCase(unittest.TestCase, CommonRequestTestTools):
      """
      Test cases for Inventory.
      """
      def setUp(self):
          self.api = mws.Inventory(
              self.CREDENTIAL_ACCESS,
              self.CREDENTIAL_SECRET,
              self.CREDENTIAL_ACCOUNT,
              auth_token=self.CREDENTIAL_TOKEN
          )
          self.api._test_request_params = True
  
      def test_list_inventory_supply(self):
          """
          ListInventorySupply operation
          """
          now = datetime.datetime.utcnow()
          now_timestamp = now.isoformat()
          skus = ['thing1', 'thing2']
          response_group = 'Detailed'
          params = self.api.list_inventory_supply(skus, now, response_group=response_group)
          self.assert_common_params(params)
          self.assertEqual(params['Action'], 'ListInventorySupply')
          self.assertEqual(params['QueryStartDateTime'], now_timestamp)
          self.assertEqual(params['ResponseGroup'], 'Detailed')
          self.assertEqual(params['SellerSkus.member.1'], 'thing1')
          self.assertEqual(params['SellerSkus.member.2'], 'thing2')
  
      def test_list_inventory_supply_by_next_token(self):
          """
          ListInventorySupplyByNextToken operation
          """
          next_token = 'token_foobar'
          params = self.api.list_inventory_supply(next_token=next_token)
          self.assert_common_params(params)
          self.assertEqual(params['Action'], 'ListInventorySupplyByNextToken')
          self.assertEqual(params['NextToken'], next_token)
  
      def test_list_inventory_supply_by_next_token_alias(self):
          """
          ListInventorySupplyByNextToken operation by way of the alias method
          list_inventory_supply_by_next_token
          """
          next_token = 'token_foobar'
          params = self.api.list_inventory_supply_by_next_token(next_token)
          self.assert_common_params(params)
          self.assertEqual(params['Action'], 'ListInventorySupplyByNextToken')
          self.assertEqual(params['NextToken'], next_token)
  
subject: Replace assert with self.assertEqual