static ServiceNaming fullTypeName() {
        return ctx -> {
            final RpcRequest rpcReq = ctx.rpcRequest();
            if (rpcReq != null) {
                return rpcReq.serviceName();
            }
            return ServiceNamingUtil.trimTrailingDollarSigns(
                    ServiceNamingUtil.fullTypeHttpServiceName(ctx.config().service()));
        };
    }
Returns the {@link ServiceNaming} that returns the full name of an RPC stub class or
the innermost class from the given service. It will be fully qualified name including the package name
separated by a period. e.g. {@code com.foo.HelloService}.

@see Class#getName()
core/src/main/java/com/linecorp/armeria/server/ServiceNaming.java