abstract-class-not-used / R0921ΒΆ
abstract-class-not-used has been removed in pylint 1.4.3. See https://pylint.readthedocs.io/en/latest/whatsnew/1/1.4.html#what-s-new-in-pylint-1-4-3 for the rationale.
Original message text:
Abstract class not referenced