Implement property uses throw UnsupportedOperationException() instead of default value or ?

idea/testData/codeInsight/overrideImplement/functionProperty.kt.after

@@ -4,9 +4,9 @@ trait A {
 }
 
 fun some() : A {
-    return object : A {<caret>
+    return object : A {
         override val method: () -> Unit?
-            get() = ?
+            get() = <selection><caret>throw UnsupportedOperationException()</selection>
     }
 }