IrFunction public fun test(): kotlin.Unit
  IrExpressionBody
    BLOCK type=<no-type> hasResult=false isDesugared=false
      VAR val a: A
        CALL .<init> type=A operator=
      CALL .plusAssign type=kotlin.Unit operator=PLUSEQ
        $receiver: GET_VAR a type=A
        s: ? IrStringConcatenationExpressionImpl type=kotlin.String
