How to extend array to support .paginate with will_paginate

will_paginate_array_helper.rb

# See http://rubydoc.info/gems/will_paginate/2.3.15/WillPaginate/Collection.create
# See https://github.com/mislav/will_paginate/blob/master/lib/will_paginate/array.rb
# Do in application_helper.rb or application_controller.rb (or somewhere else application-wide)
require 'will_paginate/collection'
Array.class_eval do
  def paginate(options = {})
    raise ArgumentError, "parameter hash expected (got #{options.inspect})" unless Hash === options

    WillPaginate::Collection.create(
        options[:page] || 1,
        options[:per_page] || 30,
        options[:total_entries] || self.length
    ) { |pager|
      pager.replace self[pager.offset, pager.per_page].to_a
    }
  end
end


# Now you can paginate any array, something like
# @posts = NewsPost.search params[:search], :match_mode => :boolean, :field_weights => {:title => 20, :summary => 15}
# filter_by_user
# @posts = @posts.paginate :page => params[:page], :order => 'published_at DESC', :per_page => NewsPost.per_page

Hi.. Where should I mention this require 'will_paginate/array' ? In which file? Knidly pls help