UFile (package = ) [public class Foo {...]
    UClass (name = Foo) [public class Foo {...}]
        UMethod (name = bar) [public fun bar(x: java.lang.String) : void {...}]
            UParameter (name = x) [var x: java.lang.String]
            UBlockExpression [{...}] = Undetermined
                UDeclarationsExpression [var f: java.lang.String = x + "1"] = Undetermined
                    ULocalVariable (name = f) [var f: java.lang.String = x + "1"]
                        UBinaryExpression (operator = +) [x + "1"] = "01"
                            USimpleNameReferenceExpression (identifier = x) [x] = "0"
                            ULiteralExpression (value = "1") ["1"] = "1"
