UFile (package = )
    UClass (name = ReceiverFunKt)
        UMethod (name = foo)
            UParameter (name = $this$foo)
                UAnnotation (fqName = MyReceiverAnnotation)
                UAnnotation (fqName = org.jetbrains.annotations.NotNull)
            UBlockExpression
                UReturnExpression
                    UQualifiedReferenceExpression
                        UThisExpression (label = null)
                        USimpleNameReferenceExpression (identifier = length)
        UMethod (name = getRx)
            UParameter (name = $this$rx)
                UAnnotation (fqName = MyReceiverAnnotation)
                    UNamedExpression (name = name)
                        ULiteralExpression (value = "RegExp")
                UAnnotation (fqName = org.jetbrains.annotations.NotNull)
            UBlockExpression
                UReturnExpression
                    UCallExpression (kind = UastCallKind(name='method_call'), argCount = 0))
                        UIdentifier (Identifier (toRegex))
                        USimpleNameReferenceExpression (identifier = toRegex, resolvesTo = null)
    UClass (name = MyReceiverAnnotation)
        UAnnotationMethod (name = name)
            ULiteralExpression (value = "")
