@Override
    public void endHandler(IAsyncHandler<Void> endHandler) {
        this.endHandler = endHandler;
    }
@see io.apiman.gateway.engine.io.IReadStream#endHandler(io.apiman.gateway.engine.async.IAsyncHandler)
test/policies/src/main/java/io/apiman/test/policies/PolicyTesterApiConnectionResponse.java