// CHECK:
//   Mangled name: #testWithNullCheck(){}
//   Public signature: /testWithNullCheck|3877804200563740268[0]
//   Public signature debug description: testWithNullCheck(){}
fun testWithNullCheck(): Unit

// CHECK JVM_IR:
//   Mangled name: #useTX(0:0;kotlin.Function0<0:0>){0§<kotlin.Any?>}0:0
//   Public signature: /useTX|-6964391636652065512[0]
//   Public signature debug description: useTX(0:0;kotlin.Function0<0:0>){0§<kotlin.Any?>}0:0
fun <T : Any?> useTX(x: T, fn: Function0<T>): T

