operator fun String.plus(some: List<Int>): String
                    infix fun Int.plus(some: List<Int>): Int
                }
            """
        ) {
            assertHasErrors(
                "Method com.example.Source.plus(java.lang.String,java.util.List): Breaking Kotlin modifier change.",
                "Method com.example.Source.plus(int,java.util.List): Breaking Kotlin modifier change.",