Package org.apache.calcite.linq4j.function

Annotation Type Experimental

@Target({PACKAGE,TYPE,FIELD,METHOD,CONSTRUCTOR})
@Retention(SOURCE)
public @interface Experimental

Annotation that indicates that a class, interface, field or method is experimental, not part of the public API, and subject to change or removal.

And yes, it is flagged experimental. We may move it elsewhere in future, when we re-think the maturity model.