UFile (package = )
    UClass (name = NonTrivialIdentifiersKt)
        UMethod (name = main)
            UParameter (name = a)
            UBlockExpression
                [!] UnknownKotlinExpression (CALL_EXPRESSION)
                [!] UnknownKotlinExpression (PROPERTY)
                [!] UnknownKotlinExpression (CALL_EXPRESSION)
    UClass (name = A)
        UMethod (name = A)
        UMethod (name = invoke)
            UBlockExpression
                [!] UnknownKotlinExpression (CALL_EXPRESSION)
        UMethod (name = invoke)
            UParameter (name = f)
            UBlockExpression
