code: protected Renderer build() {
      validateAttributes();
  
      Renderer renderer;
      if (isRecyclable(convertView, content)) {
        renderer = recycle(convertView, content);
      } else {
        renderer = createRenderer(content, parent);
      }
      return renderer;
    }
docs: Main method of this class related to ListView widget. This method is the responsible of
  recycle or create a new Renderer instance with all the needed information to implement the
  rendering. This method will validate all the attributes passed in the builder constructor and
  will check if can recycle or has to create a new Renderer instance.
  
  This method is used with ListView because the view recycling mechanism is implemented in this
  class. RecyclerView widget will use buildRendererViewHolder method.
  
  @return ready to use Renderer instance.