Shared build service abstract class failing to compile

I’m trying to implement the Shared Build Services as a groovy script to be run with gradle task as documented in Shared Build Services . But run into following codenarc compile failure “AbstractClassWithoutAbstractMethod” for the line

public abstract class WebServer implements BuildService<WebServer.Params>, AutoCloseable {

Based on the documentation i understand that BuildService.getParameters() method should not be implemented.

Can any one help me understand what’s wrong?