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: comment.rb
    path of file: ./repos/bluedoc/app/models
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class Comment < ApplicationRecord
  include SoftDelete
  include Reactionable
  include Mentionable
  include Activityable

  depends_on :watches, :notifications, :user_actives

  belongs_to :commentable, polymorphic: true, counter_cache: true, required: false
  belongs_to :user, required: false
  belongs_to :
    
  def commentable_title
    case commentable_type
    when "Doc"
      doc = commentable
      return "" if doc.blank?
      [doc.repository&.user&.name, doc.repository&.name, commentable&.title].join(" / ")
    when "Issue" then commentable&.issue_title || ""
    when "InlineComment" then commentable&.title || ""
    else
      ""
    end
  end

  def to_url
    case commentable_type
    when "Doc" then commentable&.to_url(anchor: "comment-#{id}")
    when "Issue" then commentable&.to_url(anchor: "comment-#{id}")
    when "InlineComment"
      commentable&.to_url
    else
      ""
    end
  end