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: calendaring.rb
    path of file: ./repos/circulate/app/controllers/concerns
    
    the code of the file until where you have to start completion: module Calendaring
  extend ActiveSupport::Concern

  def sync_upcoming_events
    Date.beginning_of_week = :sunday
    cutoff = Time.current + 60.days
    result = google_calendar.upcoming_events(Time.current.beginning_of_day, cutoff)
    if result.success?
      Event.update_events(result.value)
    else
      @events = []
      flash.now[
    
  def event_signup(event_id)
    @attendee = Attendee.new(email: session[:email], name: session[:name])
    result = google_calendar.add_attendee_to_event(@attendee, event_id)
    if result.success?
      Event.update_event(result.value)
      redirect_to volunteer_shifts_url, success: "You have signed up for the shift.", status: :see_other
    else
      Rails.logger.error(result.error)
      Raven.capture_message(result.error.inspect)
      redirect_to volunteer_event_url(event_ids: [event_id]), error: result.error, status: :see_other
    end