[logback-user] ch.qos.logback.classic.sift.GSiftingAppender not found in version 1.1.1

Hi, just upgrade to version 1.1.1, but an error shows ch.qos.logback.classic.sift.GSiftingAppender not found. I am using groovy to configure logback. In the document, it is mentioned that since 1.0.12, groovy configuration for SiftingAppender is not supported. Then, what is the alternative for newer version?