Remove codes related to old versions of Django.

model_utils/managers.py

@@ -1,6 +1,5 @@
 import warnings
 
-import django
 from django.core.exceptions import ObjectDoesNotExist
 from django.db import connection
 from django.db import models
@@ -96,18 +95,11 @@ class InheritanceQuerySetMixin:
         return super()._chain(**kwargs)
 
     def _clone(self, klass=None, setup=False, **kwargs):
-        if django.VERSION >= (2, 0):
-            qs = super()._clone()
-            for name in ['subclasses', '_annotated']:
-                if hasattr(self, name):
-                    setattr(qs, name, getattr(self, name))
-            return qs
-
+        qs = super()._clone()
         for name in ['subclasses', '_annotated']:
             if hasattr(self, name):
-                kwargs[name] = getattr(self, name)
-
-        return super()._clone(**kwargs)
+                setattr(qs, name, getattr(self, name))
+        return qs
 
     def annotate(self, *args, **kwargs):
         qset = super().annotate(*args, **kwargs)

model_utils/tracker.py

@@ -1,7 +1,6 @@
 from copy import deepcopy
 from functools import wraps
 
-import django
 from django.core.exceptions import FieldError
 from django.db import models
 from django.db.models.fields.files import FileDescriptor
@@ -95,7 +94,7 @@ class FieldInstanceTracker:
 
     @property
     def deferred_fields(self):
-        return self.instance._deferred_fields if django.VERSION < (1, 10) else self.instance.get_deferred_fields()
+        return self.instance.get_deferred_fields()
 
     def get_field_value(self, field):
         return getattr(self.instance, self.field_map[field])
@@ -213,12 +212,11 @@ class FieldTracker:
         if self.fields is None:
             self.fields = (field.attname for field in sender._meta.fields)
         self.fields = set(self.fields)
-        if django.VERSION >= (1, 10):
-            for field_name in self.fields:
-                descriptor = getattr(sender, field_name)
-                wrapper_cls = DescriptorWrapper.cls_for_descriptor(descriptor)
-                wrapped_descriptor = wrapper_cls(field_name, descriptor, self.attname)
-                setattr(sender, field_name, wrapped_descriptor)
+        for field_name in self.fields:
+            descriptor = getattr(sender, field_name)
+            wrapper_cls = DescriptorWrapper.cls_for_descriptor(descriptor)
+            wrapped_descriptor = wrapper_cls(field_name, descriptor, self.attname)
+            setattr(sender, field_name, wrapped_descriptor)
         self.field_map = self.get_field_map(sender)
         models.signals.post_init.connect(self.initialize_tracker)
         self.model_class = sender

tests/test_inheritance_iterable.py

@@ -1,6 +1,3 @@
-from unittest import skipIf
-
-import django
 from django.test import TestCase
 from django.db.models import Prefetch
 
@@ -8,7 +5,6 @@ from tests.models import InheritanceManagerTestParent, InheritanceManagerTestChi
 
 
 class InheritanceIterableTest(TestCase):
-    @skipIf(django.VERSION[:2] == (1, 10), "Django 1.10 expects ModelIterable not a subclass of it")
     def test_prefetch(self):
         qs = InheritanceManagerTestChild1.objects.all().prefetch_related(
             Prefetch(