isSubAdapter

Note: this is an advanced usage of RecyclerBinder that requires much more manual hand-holding of the RecyclerBinder than normal usage.

In sub adapter mode, the RecyclerBinder doesn't control the entire RecyclerView, but instead just a part of it. This means that the RecyclerBinder can't mount to a RecyclerView and set its adapter, and it won't set a scroll listener on the RecyclerView.

Instead, the internal adapter will need to be used/observed and plugged into some sort of multi-adapter that can multiplex the RecyclerView's requests between the different sub adapters.

Additionally, since the RecyclerBinder will never mount to a RecyclerView, the owner of this RecyclerBinder must manually dispatch updateSubAdapterVisibleRange and updateSubAdapterWorkingRange events if this RecyclerBinder can contains more than a screens worth of content.