'Test that passing write_concern works'

def test_update_write_concern(self):

    self.Person.drop_collection()
    write_concern = {'fsync': True}
    author = self.Person.objects.create(name='Test    User')
    author.save(write_concern=write_concern)
    result = self.Person.objects.update(set__name='Ross', write_concern={'w': 1})
    self.assertEqual(result, 1)
    result = self.Person.objects.update(set__name='Ross', write_concern={'w': 0})
    self.assertEqual(result, None)
    result = self.Person.objects.update_one(set__name='Test    User', write_concern={'w': 1})
    self.assertEqual(result, 1)
    result = self.Person.objects.update_one(set__name='Test    User', write_concern={'w': 0})
    self.assertEqual(result, None)
