Bug on swipeRefreshLayout

When I write like this,
```
override fun view() {
frameLayout {
size(FILL,FILL)
swipeRefreshLayout {
size(FILL,FILL)
}
}
}
```
Error will occur like this.
```
E/InputEventReceiver: Exception dispatching input event.
E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback
E/MessageQueue-JNI: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.view.View.canScrollVertically(int)' on a null object reference
at android.support.v4.view.ViewCompatICS.canScrollVertically(ViewCompatICS.java:40)
at android.support.v4.view.ViewCompat$ICSViewCompatImpl.canScrollVertically(ViewCompat.java:1352)

```