docs: protected void moveSelectionDown() {
  		final IStructuredSelection selection = this.list.getStructuredSelection();
  		final int index = this.conversions.indexOf(selection.getFirstElement());
  		if (index >= 0 && (index + selection.size()) < this.conversions.size()) {
  			final ConversionMapping next = this.conversions.remove(index + selection.size());
  			this.conversions.add(index, next);
  			refreshListUI();
  			this.list.refresh(true);
  			enableButtons();
  			preferenceValueChanged();
  		}
  	}