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: 20210322164601_create_account_summaries.rb
    path of file: ./repos/mastodon/db/migrate
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class CreateAccountSummaries < Active
    
  def change
    create_view :account_summaries, materialized: true

    # To be able to refresh the view concurrently,
    # at least one unique index is required
    safety_assured { add_index :account_summaries, :account_id, unique: true }
  end