def all(self, func=None):
        """ Determine whether all of the elements match a truth test.
        """
        if func is None:
            func = lambda x, *args: x
        self.altmp = True

        def testEach(value, index, *args):
            if func(value, index, *args) is False:
                self.altmp = False

        self._clean.each(testEach)
        return self._wrap(self.altmp)