You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: checkin_presenter.rb
    path of file: ./repos/onebody/app/presenters
    
    the code of the file until where you have to start completion: class CheckinPresenter
  extend ActiveModel::Naming

  attr_reader :campus, :family

  def initialize(campus, family = nil)
    @campus = campus
    @family = family
  end

  def id
    family.id
  end

  def times
    checkin_times.decorate
  end

  def group_ids
    @group_ids ||= checkin_times.flat_map { |t| t.all_group_times.pluck(:grou
    
  def checkin_times
    @checkin_times ||= CheckinTime.where(campus: @campus)
                                  .where(
                                    "(the_datetime is null and weekday = :today) or
                                     (the_datetime between :from and :to)",
                                    today: Time.current.wday,
                                    from:  1.hour.ago.strftime('%Y-%m-%dT%H:%M:%S'),
                                    to:    4.hours.from_now.strftime('%Y-%m-%dT%H:%M:%S')
                                  )
  end