@Override
 public void onLinesChanged() {
   linesAdapter.onLinesChanged();
   maybeChangeHeader();
 }
 @Override
 public void onLinesListed() {
   linesAdapter.onLinesChanged();
   maybeChangeHeader();
   scrollToHotLineIfNeeded();
 }
 @Override
 public void onLinesChanged() {
   linesAdapter.onLinesChanged();
 }