class ActionView::PartialRenderer

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