def METHOD_NAME(self):
    with realized(self.bar):
        self.failUnless(self.bar.can_filter(None))
        self.failUnless(self.bar.can_filter("album"))
        self.failUnless(self.bar.can_filter("foobar"))
        self.failIf(self.bar.can_filter("~#length"))
        self.failIf(self.bar.can_filter("title"))