@Override
	public void dataChanged(boolean updateImmediately) {
		cache.clear();
		for (ListingModelListener listener : listeners) {
			listener.dataChanged(updateImmediately);
		}
	}
Returns the ListingLayoutModel for the i'th program.
@param index the index of program for which to return a listing model
@return the ListingLayoutModel for the i'th program.
Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/multilisting/MultiListingLayoutModel.java