在Java8中，我们可以引用类实例的方法.这里有一个例子
Function1<Integer, Object> ref = a::getItem;
A是具有方法Object getItem(int i)的类Adapter的实例.
Can we do the same in Kotlin? I tried the same syntax without success. So far I was only able to create an extension method reference like so:
val ref: Adapter.(Int) -> Any = Adapter::getItem
但是在这里，我仍然需要一个Adapter的实例来调用它.我看到的另一个备选方案是这样定义一个lambda:
val ref: (Int) -> Any = { a.getItem(it) }