DSL syntax vs Java syntax in a RuleSource plug-in

Hi guys
A small question

I’m writing a RuleSource plugin with sth like

@Mutate
void createPublicationRepository(PublishingExtension publishing){
    publishing.repositories {
        maven {
            url 'http://artifactory:8081/artifactory/xxx/'
            credentials {
                username 'yyy'
                password 'zzz'
            }
        }
    }
}

When publishing, this fails with a 401 'unauthorized ’ error

When using the java syntax

@Mutate
void createPublicationRepository(PublishingExtension publishing){
    publishing.getRepositories().maven {
        url 'http://artifactory:8081/artifactory/xxx/'
        credentials {
            username 'yyy'
            password 'zzz'
        }
    }
}

This works as expected