def remove_class(rem_class)
      @modules.each do |m|
        if m.name == rem_class.name
          m.classes.delete(rem_class)
          break
        end
      end
    end
def remove_class(rem_class)
      @modules.each do |m|
        if m.name == rem_class.name
          m.classes.delete(rem_class)
          break
        end
      end
    end
Removes a class from the timetable