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: suggested_edit.rb
    path of file: ./repos/qpixel/app/models
    
    the code of the file until where you have to start completion: class SuggestedEdit < ApplicationRecord
  include PostRelated
  include PostValidations
  include EditsValidations

  belongs_to :user

  serialize :tags_cache, Array
  serialize :before_tags_cache, Array

  belongs_to :decided_by, class_name: 'User', optional: true
  has_and_belongs_to_
    
  def update_tag_associations
    return if tags_cache.nil? # Don't update if this doesn't affect tags

    tags_cache.each do |tag_name|
      tag = Tag.find_or_create_by name: tag_name, tag_set: post.category.tag_set
      unless tags.include? tag
        tags << tag
      end
    end

    tags.each do |tag|
      unless tags_cache.include? tag.name
        tags.delete tag
      end
    end