code: private void applyFilter(){
          filteredItems.clear();
  
          Filter<M> filter = getFilter();
          if(filter == null){
              filteredItems.addAll(items);
          }else{
              for (int i = 0; i < items.size(); i++) {
                  M item = items.get(i);
                  if(filter.filter(item, query)){
                      filteredItems.add(item);
                  }
              }
          }
  
          onFiltered();
      }
docs: Apply the filter, if possible, to the adapter to update content