# File lib/core/world.rb, line 95
  def unset_timer(id, name=nil)
    @timer_list_mutex.synchronize do
      if name.nil?
        timer_list.delete_if {|ti| ti.id == id }
      else
        timer_list.delete_if {|ti| ti.id == id && ti.name == name }
      end
    end
  end