# File lib/ruby-prof/graph_html_printer.rb, line 75
    def calculate_thread_times
      # Cache thread times since this is an expensive
      # operation with the required sorting
      @overall_threads_time = 0.0
      @thread_times = Hash.new
      @result.threads.each do |thread_id, methods|
        roots = methods.select{|m| m.root?}
        thread_total_time = sum(roots.map{|r| self.total_time(r.call_infos)})
        @overall_threads_time += thread_total_time
        @thread_times[thread_id] = thread_total_time
      end
    end