```ruby
class User < ActiveRecord::Base

      has_many :games

	validates_presence_of :username, :email, :password_digest, unless: :guest?
	validates_uniqueness_of :username, allow_blank: true

      require 'bcrypt'
      attr_reader :password
      include ActiveModel::SecurePassword::InstanceMethodsOnActivation

      def name
        guest ? "Guest" : username
      end

  def self.new_guest
    new { |u| u.guest = true }
  end

  def move_to(user)
    games.update_all(user_id: user.id)
  end

end
```

Remove unnecessary move to method
user
```ruby
class User < ActiveRecord::Base

      has_many :games

	validates_presence_of :username, :email, :password_digest, unless: :guest?
	validates_uniqueness_of :username, allow_blank: true

      require 'bcrypt'
      attr_reader :password
      include ActiveModel::SecurePassword::InstanceMethodsOnActivation

      def name
        guest ? "Guest" : username
      end

  def self.new_guest
    new { |u| u.guest = true }
  end

end
```
assistant