@Override
    public Class[] services() {
        return new Class[] {
            SpanForwardService.class
        };
    }
Zipkin receiver module provides the HTTP, protoc serve for any SDK or agent by following Zipkin format.
<p>
At this moment, Zipkin format is not compatible with SkyWalking, especially HEADERs. Please don't consider this as a
Zipkin-SkyWalking integration, it is provided for adding analysis, aggregation and visualization capabilities to
zipkin backend.
oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/ZipkinReceiverModule.java