Traceback (most recent call last):


 "test.py", line 18, in <module>

f(D)


 "test.py", line 16, in f

return cls()
TypeError: Can't instantiate abstract class D with abstract methods f

Traceback (most recent call last):


 "/usr/lib64/python3.6/site-packages/nose/case.py", line 197, in runTest

self.test(*self.arg)
TypeError: test_save_settings() missing 1 required positional argument: 'tmpdir'
