diff --git a/common/lib/xmodule/xmodule/modulestore/tests/test_cross_modulestore_import_export.py b/common/lib/xmodule/xmodule/modulestore/tests/test_cross_modulestore_import_export.py
index 6763838fde..23a8c21f6b 100644
--- a/common/lib/xmodule/xmodule/modulestore/tests/test_cross_modulestore_import_export.py
+++ b/common/lib/xmodule/xmodule/modulestore/tests/test_cross_modulestore_import_export.py
@@ -16,8 +16,7 @@ import ddt
 import itertools
 import random
 from contextlib import contextmanager, nested
-from functools import partial
-from unittest import TestCase
+from unittest import SkipTest
 from shutil import rmtree
 from tempfile import mkdtemp
 from opaque_keys.edx.locations import SlashSeparatedCourseKey
@@ -46,9 +45,23 @@ class MemoryCache(object):
         self._data = {}
 
     def get(self, key, default=None):
+        """
+        Get a key from the cache.
+
+        Args:
+            key: The key to update.
+            default: The value to return if the key hasn't been set previously.
+        """
         return self._data.get(key, default)
 
     def set(self, key, value):
+        """
+        Set a key in the cache.
+
+        Args:
+            key: The key to update.
+            value: The value change the key to.
+        """
         self._data[key] = value
 
 
@@ -113,6 +126,8 @@ class VersioningModulestoreBuilder(object):
             contentstore: The contentstore that this modulestore should use to store
                 all of its assets.
         """
+        # pylint: disable=unreachable
+        raise SkipTest("DraftVersioningModuleStore doesn't yet support the same interface as the rest of the modulestores")
         doc_store_config = dict(
             db='modulestore{}'.format(random.randint(0, 10000)),
             collection='split_module',
@@ -142,6 +157,7 @@ class VersioningModulestoreBuilder(object):
     def __repr__(self):
         return 'SplitModulestoreBuilder()'
 
+
 class MixedModulestoreBuilder(object):
     """
     A builder class for a MixedModuleStore.
@@ -221,6 +237,7 @@ MODULESTORE_SETUPS = (
 CONTENTSTORE_SETUPS = (MongoContentstoreBuilder(),)
 COURSE_DATA_NAMES = ('toy', 'test_unicode')
 
+
 @ddt.ddt
 class CrossStoreXMLRoundtrip(CourseComparisonTest):
     """
@@ -242,7 +259,6 @@ class CrossStoreXMLRoundtrip(CourseComparisonTest):
     ))
     @ddt.unpack
     def test_round_trip(self, source_builder, dest_builder, source_content_builder, dest_content_builder, course_data_name):
-        self.maxDiff = None
         source_course_key = SlashSeparatedCourseKey('source', 'course', 'key')
         dest_course_key = SlashSeparatedCourseKey('dest', 'course', 'key')
 
diff --git a/common/lib/xmodule/xmodule/tests/__init__.py b/common/lib/xmodule/xmodule/tests/__init__.py
index e7c8e06912..eaedb54da7 100644
--- a/common/lib/xmodule/xmodule/tests/__init__.py
+++ b/common/lib/xmodule/xmodule/tests/__init__.py
@@ -176,6 +176,12 @@ class CourseComparisonTest(unittest.TestCase):
         self.field_exclusions.add((usage_id, field_name))
 
     def ignore_asset_key(self, key_name):
+        """
+        Add an asset key to the list of keys to be ignored when comparing assets.
+
+        Args:
+            key_name: The name of the key to ignore.
+        """
         self.ignored_asset_keys.add(key_name)
 
     def assertCoursesEqual(self, expected_store, expected_course_key, actual_store, actual_course_key):
@@ -253,6 +259,9 @@ class CourseComparisonTest(unittest.TestCase):
                 self.assertEqual(expected_children, actual_item.children)
 
     def assertAssetEqual(self, expected_course_key, expected_asset, actual_course_key, actual_asset):
+        """
+        Assert that two assets are equal, allowing for differences related to their being from different courses.
+        """
         for key in self.ignored_asset_keys:
             if key in expected_asset:
                 del expected_asset[key]
@@ -270,7 +279,10 @@ class CourseComparisonTest(unittest.TestCase):
         self.assertEqual(actual_key.to_deprecated_string(), actual_filename)
         self.assertEqual(expected_asset, actual_asset)
 
-    def _assertAssetsEqual(self, expected_course_key, expected_assets, actual_course_key, actual_assets):
+    def _assertAssetsEqual(self, expected_course_key, expected_assets, actual_course_key, actual_assets):  # pylint: disable=invalid-name
+        """
+        Private helper method for assertAssetsEqual
+        """
         self.assertEqual(len(expected_assets), len(actual_assets))
 
         actual_assets_map = {asset['asset_key']: asset for asset in actual_assets}