fix formatting issues for list serializer validation fix

rest_framework/serializers.py

@@ -612,7 +612,7 @@ class ListSerializer(BaseSerializer):
 
         if kwargs.get('instance', []) and kwargs.get('data', []):
             assert len(kwargs.get("data", [])) == len(
-            kwargs.get("instance", [])), 'Data and instance should have same length'
+                kwargs.get("instance", [])), 'Data and instance should have same length'
 
         super().__init__(*args, **kwargs)
         self.child.bind(field_name='', parent=self)

tests/test_serializer.py

@@ -11,7 +11,6 @@ from django.db import models
 
 from rest_framework import exceptions, fields, relations, serializers
 from rest_framework.fields import Field
-
 from .models import (
     ForeignKeyTarget, NestedForeignKeySource, NullableForeignKeySource
 )
@@ -837,10 +836,10 @@ class TestMultipleObjectsValidation(unittest.TestCase):
     def test_exception_raised_when_data_and_instance_length_different(self):
 
         with self.assertRaises(AssertionError):
-            serializer = MyClassSerializer(
+            MyClassSerializer(
                 data=[{'value': 'set', 'id': instance.id} for instance in
                       self.objs],
                 instance=self.objs[:-1],
                 many=True,
                 partial=True,
-            )
+            )