code: @Override public Object instantiateItem(ViewGroup parent, int position) {
          T content = getItem(position);
          rendererBuilder.withContent(content);
          rendererBuilder.withParent(parent);
          rendererBuilder.withLayoutInflater(LayoutInflater.from(parent.getContext()));
          Renderer<T> renderer = rendererBuilder.build();
          if (renderer == null) {
              throw new NullRendererBuiltException("RendererBuilder have to return a not null Renderer");
          }
          updateRendererExtraValues(content, renderer, position);
          renderer.render();
          View view = renderer.getRootView();
          parent.addView(view);
          return view;
      }
docs: Main method of VPRendererAdapter. This method has the responsibility of update the
  RendererBuilder values and create or recycle a new Renderer. Once the renderer has been
  obtained the RendereBuilder will call the render method in the renderer and will return the
  Renderer root view to the ViewPager.
  
  If RendererBuilder returns a null Renderer this method will throw a
  NullRendererBuiltException.
  
  @param parent The containing View in which the page will be shown.
  @param position to render.
  @return view rendered.