class ActionView::PartialRenderer

def render(context, options, block)
  setup(context, options, block)
  identifier = (@template = find_partial) ? @template.identifier : @path
  @lookup_context.rendered_format ||= begin
    if @template && @template.formats.present?
      @template.formats.first
    else
      formats.first
    end
  end
  if @collection
    instrument(:collection, :identifier => identifier || "collection", :count => @collection.size) do
      render_collection
    end
  else
    instrument(:partial, :identifier => identifier) do
      render_partial
    end
  end
end