@SuppressWarnings("unchecked")
    @Override
    public void processFailure(PolicyFailure failure, IPolicyContext context, Object config, IPolicyFailureChain chain) {
        doProcessFailure(failure, context, (C) config, chain);
    }
Apply the policy to the response.
<p>
Override this method to interact with or observe the response.

@param response the response
@param context the policy context
@param config the configuration (see {@link #getConfigurationClass()})
@param chain the ordered policy chain
gateway/engine/policies/src/main/java/io/apiman/gateway/engine/policies/AbstractMappedPolicy.java