DRF docs - getting serializers dynamically - django-rest-framework

Question

I have a viewset which uses different serializers for different HTTP methods (and possibly even for different users). DRF docs says this:
To be compatible with this behaviour methods (such as get_serializer or
get_serializer_class etc.) which inspect self.request or, particularly,
self.request.user may need to be adjusted to handle this case.
Can anyone provide me an example of the "adjustment to handle this case"?
Say I have a viewset which is using serializer A for get method for admins, serializer B for get method for all other users and serializer C for all other methods. How to specify this so that the documentation understands this? I am using the builtin one.
My urls.py:
router = DefaultRouter()
router.register('test', SampleViewset, base_name="test")
urlpatterns = [
path('admin/', admin.site.urls),
path('docs/', include_docs_urls(title='My API title', public=True)),
path('', include(router.urls)),
]

Answer 1

Minimal example
models.py
class SampleModel(models.Model):
name = models.CharField(max_length=120)
age = models.IntegerField()
address = models.CharField(max_length=100)
serializers.py
class SampleSerializer(serializers.ModelSerializer):
class Meta:
fields = '__all__'
model = SampleModel
class SampleSerializerCreate(serializers.ModelSerializer):
age = serializers.IntegerField(max_value=20)
class Meta:
fields = '__all__'
model = SampleModel
views.py
class SampleViewset(ModelViewSet):
serializer_class = SampleSerializer
queryset = SampleModel.objects.all()
def get_serializer_class(self):
if self.action=='create':
return SampleSerializerCreate
return SampleSerializer
Here I used a logic that, while creation of SampleModel, the age attribute should not exceed a max_value of 20.
Update-1
from rest_framework.routers import DefaultRouter
router = DefaultRouter()
router.register(r'sample', SampleViewset)
urlpatterns = [
path('docs/', include_docs_urls(title='My API title', public=True, patterns=router.urls)),
] + router.urls