extract insert and add topics methods

category_list.rb

def insert_uncategorized_category(uncategorized)
  insert_at = nil
  @categories.each_with_index do |c, idx|
    if (uncategorized.topics_week || 0) > (c.topics_week || 0)
      insert_at = idx
      break
    end
  end

  @categories.insert(insert_at || @categories.size, uncategorized)  
end

def add_uncategorized_topics(uncategorized_topics)
  if @all_topics.present? && uncategorized.present?
    uncategorized.displayable_topics = uncategorized_topics
    @all_topics << uncategorized_topics
    @all_topics.flatten!
  end  
end