          self.assertEqual(getattr(serializer.fields['slug_field'], 'max_length'), 84)
  
      def test_given_serializer_value(self):
          class SlugFieldSerializer(serializers.ModelSerializer):
              slug_field = serializers.SlugField(source='slug_field', max_length=20, required=False)
  
              class Meta:
                  model = self.SlugFieldModel
  
          serializer = SlugFieldSerializer(data={})
 
</s> remove             url_field = serializers.URLField(source='url_field', max_length=20, required=False)
 </s> add             url_field = serializers.URLField(source='url_field',
                                             max_length=20, required=False) </s> remove         self.assertEqual(getattr(serializer.fields['slug_field'], 'max_length'), 20)
 </s> add         self.assertEqual(getattr(serializer.fields['slug_field'],
                                 'max_length'), 20) </s> remove         self.assertEqual(getattr(serializer.fields['url_field'], 'max_length'), 128)
 </s> add         self.assertEqual(getattr(serializer.fields['url_field'],
                                 'max_length'), 128) </s> remove         self.assertEqual(getattr(serializer.fields['url_field'], 'max_length'), 200)
 </s> add         self.assertEqual(getattr(serializer.fields['url_field'],
                                 'max_length'), 200) </s> remove class Form(forms.Form):
    field1 = forms.CharField(max_length=3, label='field one')
    field2 = forms.CharField(label='field two')
 </s> add class HumanizableSerializer(Serializer):
    field1 = CharField(3, required=True)
    field2 = CharField(10, required=False)
            slug_field = serializers.SlugField(source='slug_field',
                                               max_length=20, required=False)
          self.assertEqual(getattr(serializer.fields['slug_field'], 'max_length'), 84)
  
      def test_given_serializer_value(self):
          class SlugFieldSerializer(serializers.ModelSerializer):
            slug_field = serializers.SlugField(source='slug_field',
                                               max_length=20, required=False)
  
              class Meta:
                  model = self.SlugFieldModel
  
          serializer = SlugFieldSerializer(data={})
keep keep keep keep replace keep keep keep keep keep
 simplified, moved field humanizing to Field. broken tests 
rest_framework/tests/fields.py