@abc.abstractproperty
    def key_size(self):
Helper method that checks a single attribute and gives a nice error
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/cryptography-1.3.1/src/cryptography/hazmat/primitives/ciphers/base.py/CipherAlgorithm.key_size--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/tests/regressiontests/pagination_regress/tests.py/PaginatorTests.check_attribute