@SuppressWarnings("nls")
    @Override
    protected void doApply(ApiRequest request, IPolicyContext context, SimpleReplacementBean config,
            IPolicyChain<ApiRequest> chain) {
        request.getHeaders().put("X-Field-1", config.getField1());
        request.getHeaders().put("X-Field-2", config.getField2());
        request.getHeaders().put("X-Field-3", config.getField3());
        super.doApply(request, context, config, chain);
    }
@see io.apiman.gateway.engine.policies.AbstractMappedPolicy#doApply(io.apiman.gateway.engine.beans.ApiRequest, 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/SimpleReplacementPolicy.java