toExpect
inline fun <R : Any> toExpect(crossinline assertionCreator: Expect<R>.(T) -> Unit): Pair<Expect<R>.() -> Unit?, Array<out Expect<R>.() -> Unit?>>(source)
Maps each argument to null if it is already null and if not, then to an Expect<R> lambda with receiver by using the given assertionCreator (passing in the argument).