*
* @see #showFilterField(Function)
*/
public void showFilterField(Function<String, KongaTreeFilter> filterFunction, boolean closeable) {
checkNotNull(filterFunction, "filterFunction");
filterField = new TreeFilterField(tree, filterFunction);
filterField.setRemoveFilterOnClose(removeFilterWhenFilterFieldClosed);
filterField.setInterceptor(filterInterceptor);
if (closeable) {
filterField.setCloseable(new ActionListener() {