render_collection_derive_partial

# File actionview/lib/action_view/renderer/collection_renderer.rb, line 130
    def render_collection_derive_partial(collection, context, block)
      paths = collection.map { |o| partial_path(o, context) }

      if paths.uniq.length == 1
        # Homogeneous
        render_collection_with_partial(collection, paths.first, context, block)
      else
        if @options[:cached]
          raise NotImplementedError, "render caching requires a template. Please specify a partial when rendering"
        end

        paths.map! { |path| retrieve_variable(path).unshift(path) }
        collection = MixedCollectionIterator.new(collection, paths)
        render_collection(collection, context, nil, nil, nil, block)
      end
    end