[Android.Runtime.Register("unregisterAdapterDataObserver", 
   "(Landroid/support/v7/widget/RecyclerView$AdapterDataObserver;)V", 
   "GetUnregisterAdapterDataObserver_Landroid_support_v7_widget_RecyclerView_AdapterDataObserver_Handler")]
public virtual void UnregisterAdapterDataObserver( 
   Android.Support.V7.Widget.RecyclerView.AdapterDataObserver observer
)