Use more specific assertIsInstance in tests (#268)
When running tests with Python warnings enabled, warnings of the
following form appear:
DeprecationWarning: Please use assertTrue instead.
self.failUnless(isinstance(...))
Use assertIsInstance instead to fix these warnings.
Using a more specific assert also has the advantage of more informative
error reporting upon failure.
https://docs.python.org/3/library/unittest.html#unittest.TestCase.assertTrue
> This method should also be avoided when more specific methods are
> available (e.g. assertEqual(a, b) instead of assertTrue(a == b)),
> because they provide a better error message in case of failure.
3 files changed
