How to handle the fault generated by security polices.

[plvndinesh]

I attached a Security policy(VerifyApi key) to my ProxyEndpoint(request) , when i am not provind key it is throwing error like

{"fault":{"faultstring":"Failed to resolve API Key variable request.queryparam.apikey","detail":{"errorcode":"steps.oauth.v2.FailedToResolveAPIKey"}}}

I need handle this fault and generate user understandble message.

note:I tried in handling faultrules but it not worked.