'%s' object has no attribute '%s'

Raise code

rgsMixin:
    _argnames = ()  # type: tTuple[str, ...]

    def __getattr__(self, attr):
        try:
            return self.args[self._argnames.index(attr)]
        except ValueError:
            raise AttributeError("'%s' object has no attribute '%s'" % (
                type(self).__name__, attr))


class Distribution(Basic):

    def sample(self, size=(), library='scipy', seed=None):
        """ A random realization from the distribution """

        mod