@Override
            public void handle(IAsyncResult<String> result) {
                String propVal = result.getResult();
                response.getHeaders().put("X-Shared-State-Value", propVal);
                chain.doApply(response);
            }
@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)
gateway/test/src/test/java/io/apiman/gateway/test/policies/SimpleSharedStatePolicy.java