How to add custom renderer for will_paginate in merb?

Question

As I need to have pagination tags done this way:

<ul> <li> <a>some page</a> </li> </ul>

I'd like to add custom renderer to Merb app. When I put code

module SearchPagination
  class LinkRenderer < WillPaginate::ActionView::LinkRenderer
    protected
    def windowed_page_numbers
      inner_window = @options[:inner_window].to_i
      window_from = current_page
      window_to = current_page + inner_window

      # adjust upper limit if out of bounds
      window_to = total_pages if window_to > total_pages
      left = (window_from..window_to).to_a
      left << :gap if total_pages > window_to
      left
   end
 end

end

into helpers/paginate_helper.rb and then use it in view like:

<%= will_paginate @channels, :renderer => SearchPagination::LinkRenderer %>

I'm getting next error:

uninitialized constant Merb::InlineTemplates::SearchPagination - (NameError)

So, how to connect this stuff in the right way?