@Nullable
    @Override
    public String getRootPath(EndpointId endpointId) {
        final String path = pathMapping.get(endpointId);
        return StringUtils.hasText(path) ? path : null;
    }
Fork of <a href="https://github.com/spring-projects/spring-boot/blob/e3aac5913ed3caf53b34eb7750138a4ed6839549/spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/MappingWebEndpointPathMapper.java">MappingWebEndpointPathMapper</a>.
This class doesn't follow the Armeria code convention because maintenance is easier if you use the same code
as the spring side.
spring/boot3-actuator-autoconfigure/src/main/java/com/linecorp/armeria/spring/actuate/MappingWebEndpointPathMapper.java