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: create_smart_sms_messages.rb
    path of file: ./repos/smart_sms/lib/generators/smart_sms/templates
    
    the code of the file until where you have to start completion: class CreateSmartSmsMessages < ActiveRecord::Migration
  def change
    creat
    
  def change
    create_table :smart_sms_messages do |t|
      t.string :sid
      t.string :mobile
      t.datetime :send_time
      t.text :text
      t.string :code
      t.string :send_status
      t.string :report_status
      t.string :fee
      t.datetime :user_receive_time
      t.text :error_msg
      t.belongs_to :smsable, polymorphic: true
    end
    add_index :smart_sms_messages, :sid
    add_index :smart_sms_messages, [:smsable_id, :smsable_type]
  end