def test_non_callable(self):
        with pytest.raises(TypeError) as excinfo:
            event.event(123)
        excinfo.match(r"Expected string, callable or None as first argument")

        with pytest.raises(TypeError) as excinfo:
            event.event("name")([])
        excinfo.match(r"Callable must be a function \(`def`\)"
                      r" or coroutine function \(`async def`\)")
def dfs(self,can,cursum,target,res):
        if cursum > target: return 
        if cursum == target: 
            self.result.append(res)
            return 
        for i in xrange(len(can)):
            if not res or res[len(res)-1] <= can[i]:
                self.dfs(can,cursum+can[i],target,res+[can[i]])