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: purchase.rb
    path of file: ./repos/gitlabhq/qa/qa/flow
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module QA
  module Flow
    module Purchase
      include Support::Helpers::Plan

      extend self

      def upgrade_subscription(plan: PREMIUM, skip_contact: false)
        Page::Group::Menu.perform(&:go_to_billing)
        G
    
      def upgrade_subscription(plan: PREMIUM, skip_contact: false)
        Page::Group::Menu.perform(&:go_to_billing)
        Gitlab::Page::Group::Settings::Billing.perform do |billing|
          billing.send("upgrade_to_#{plan[:name].downcase}")
        end

        Gitlab::Page::Subscriptions::New.perform do |new_subscription|
          new_subscription.continue_to_billing
          fill_in_default_info(skip_contact)
          new_subscription.purchase
        end
      end