@Override
    public void processFailure(PolicyFailure failure, IPolicyContext context, Object config,  IPolicyFailureChain chain) {
        failure.getHeaders().put("Test-Policy-Process-Failure", "true");

        chain.doFailure(failure);
    }
@see io.apiman.gateway.engine.policy.IPolicy#apply(io.apiman.gateway.engine.beans.ApiResponse, io.apiman.gateway.engine.policy.IPolicyContext, java.lang.Object, io.apiman.gateway.engine.policy.IPolicyChain)
plugins/test-policy/src/main/java/io/apiman/plugins/test_policy/TestPolicy.java