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: application_helper.rb
    path of file: ./repos/sample_apps/7_0/ch04/app/helpers
    
    the code of the file until where you have to start completion: module ApplicationHelper

  # ページごとの完全なタイトルを返します。                      # コメント行
  def full_title(page_title = '')                     # メソッド定義とオプション引数
    base_title = "Ruby on Rails Tutorial Sample
    
  def full_title(page_title = '')                     # メソッド定義とオプション引数
    base_title = "Ruby on Rails Tutorial Sample App"  # 変数への代入
    if page_title.empty?                              # 論理値テスト
      base_title                                      # 暗黙の戻り値
    else
      "#{page_title} | #{base_title}"                 # 文字列の結合
    end