This code breaks the compiler for X10 2.3.1

AbstractSettable.x10

public abstract class AbstractSettable[T] implements Settable[T] {
    public operator this()=(value:T) {
        set(value);
    }
}

Settable.x10

public interface Settable[T] {
    operator this()=(value:T):void;
    def set(value:T):void;
}

SettableImpl.x10

public class SettableImpl[T] extends AbstractSettable[T] {
    private var data:T;
    
    public def this(value:T) {
        this.data = value;
    }
    
    public def set(value:T) {
        data = value;
    }
}