UFile (package = ) [public final class WhenIsKt {...]
    UClass (name = WhenIsKt) [public final class WhenIsKt {...}]
        UMethod (name = foo) [public static final fun foo(@org.jetbrains.annotations.NotNull bar: java.lang.Object) : java.lang.String {...}]
            UParameter (name = bar) [@org.jetbrains.annotations.NotNull var bar: java.lang.Object]
                UAnnotation (fqName = org.jetbrains.annotations.NotNull) [@org.jetbrains.annotations.NotNull]
            UBlockExpression [{...}]
                UReturnExpression [return switch (bar)  {...]
                    USwitchExpression [switch (bar)  {...] : PsiType:String
                        USimpleNameReferenceExpression (identifier = bar) [bar] : PsiType:Object
                        UExpressionList (when) [    it is java.lang.String -> {...    ] : PsiType:String
                            USwitchClauseExpressionWithBody [it is java.lang.String -> {...]
                                UBinaryExpressionWithType [it is java.lang.String]
                                    USimpleNameReferenceExpression (identifier = it) [it]
                                    UTypeReferenceExpression (name = java.lang.String) [java.lang.String]
                                UExpressionList (when_entry) [{...]
                                    UYieldExpression [yield bar]
                                        USimpleNameReferenceExpression (identifier = bar) [bar] : PsiType:Object
                            USwitchClauseExpressionWithBody [it !is java.lang.String -> {...]
                                UBinaryExpressionWithType [it !is java.lang.String]
                                    USimpleNameReferenceExpression (identifier = it) [it]
                                    UTypeReferenceExpression (name = java.lang.String) [java.lang.String]
                                UExpressionList (when_entry) [{...]
                                    UYieldExpression [yield "<error>"]
                                        ULiteralExpression (value = "<error>") ["<error>"] : PsiType:String
