# File karel/tk_robot_world.rb, line 196
  def remove_all_beepers(street, avenue)
    @beepers.synchronize do
         place = [street, avenue]
        # howMany = @beepers[place]
        # if howMany != nil and howMany != 0  
          @beepers.delete(place)
          if $window 
             $window.delete_beeper(place)
          end
          @@beeper_control.signal
        # end
    end
  end