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: 06_create_clicks.rb
    path of file: ./repos/postal/lib/postal/message_db/migrations
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Postal
  module MessageDB
    module Migrations
      class CreateClicks < Postal::MessageDB::Migration

        def up
          @database.provisioner.create_table(:clicks,
                                             columns: {
                                               id: "int(11) NOT NULL AUTO_INCREMENT",
                                               message_id: "int(11) DEFAULT NULL",
                                               link_id: "int(11) DEFAULT NULL",
                                               ip_address: "varchar(255) DEFAULT NULL",
                                               country: "varchar(255) DEFAULT NULL",
                                               city: "varchar(255) DEFAULT NULL",
                                               user_agent: "varchar(255) DEFAULT
    
        def up
          @database.provisioner.create_table(:clicks,
                                             columns: {
                                               id: "int(11) NOT NULL AUTO_INCREMENT",
                                               message_id: "int(11) DEFAULT NULL",
                                               link_id: "int(11) DEFAULT NULL",
                                               ip_address: "varchar(255) DEFAULT NULL",
                                               country: "varchar(255) DEFAULT NULL",
                                               city: "varchar(255) DEFAULT NULL",
                                               user_agent: "varchar(255) DEFAULT NULL",
                                               timestamp: "decimal(18,6) DEFAULT NULL"
                                             },
                                             indexes: {
                                               on_message_id: "`message_id`",
                                               on_link_id: "`link_id`"
                                             })
        end