Update astroquery/xmm_newton/tests/dummy_handler.py
Ok to use format
@@ -46,7 +46,8 @@ class DummyHandler(object):
if method == self._invokedMethod:
return
else:
- raise ValueError("".join(("Method '",
+ raise ValueError("Method '{}' is not invoked. (Invoked method is '{}'.)"
+ .format(method, self_invokedMethod))
str(method),
"' not invoked. (Invoked method is '",
str(self._invokedMethod)+"')")))
