ask key problem

gistfile1.txt

diff --git a/sympy/assumptions/tests/test_query.py b/sympy/assumptions/tests/test_query.py
index 516d0d7..ccb09fe 100644
--- a/sympy/assumptions/tests/test_query.py
+++ b/sympy/assumptions/tests/test_query.py
@@ -982,6 +982,7 @@ def Symbol(expr, assumptions):
     assert ask(Q.my_key(x)) == True
     assert ask(Q.my_key(x+1)) == None
     remove_handler('my_key', MyAskHandler)
+    raises(AttributeError, "ask(Q.my_key(x))")
 
 def test_type_extensibility():
     """test that new types can be added to the ask system at runtime