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: 20150727230537_add_example_column_comments.rb
    path of file: ./repos/discourse/db/migrate
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require "comment_migration"

class AddExampleColumnComments < CommentMigration
  def comments_up
    {
      posts
    
  def comments_up
    {
      posts: {
        _table: "If you want to query public posts only, use the badge_posts view.",
        post_number:
          "The position of this post in the topic. The pair (topic_id, post_number) forms a natural key on the posts table.",
        raw: "The raw Markdown that the user entered into the composer.",
        cooked: "The processed HTML that is presented in a topic.",
        reply_to_post_number:
          "If this post is a reply to another, this column is the post_number of the post it's replying to. [FKEY posts.topic_id, posts.post_number]",
        reply_quoted:
          "This column is true if the post contains a quote-reply, which causes the in-reply-to indicator to be absent.",
      },
      topics: {
        _table:
          "To query public topics only: SELECT ... FROM topics t LEFT INNER JOIN categories c ON (t.category_id = c.id AND c.read_restricted = false)",
      },
    }
  end