Use Paperclip without ActiveRecord

simple_paperclip.rb

# == Paperclip without ActiveRecord
#
# Simple and lightweight object that can use Paperclip
#
# 
# Customized part can be extracted in another class which
# would inherit from SimplePaperclip.
#
#   class MyClass < SimplePaperclip
#     attr_accessor :image_file_name # :<atached_file_name>_file_name
#     has_attached_file :image, styles: { medium: "300x300>", thumb: "100x100>" }
#   end
#
# author : Bastien Gysler <basgys@gmail.com>
class SimplePaperclip
  extend ActiveModel::Naming
  extend ActiveModel::Callbacks

  include ActiveModel::Validations
  include Paperclip::Glue

  # Paperclip required callbacks
  define_model_callbacks :save, only: [:after]
  define_model_callbacks :destroy, only: [:before, :after]  

  # Paperclip attached file example
  # -- Customize here --
  attr_accessor :image_file_name # :<atached_file_name>_file_name
  has_attached_file :image, styles: { medium: "300x300>", thumb: "100x100>" }
  # -- /Customize here --

  # ActiveModel requirements  
  def to_model
    self
  end
 
  def valid?()      true end
  def new_record?() true end
  def destroyed?()  true end

  def errors
    obj = Object.new
    def obj.[](key)         [] end
    def obj.full_messages() [] end
    obj
  end  
end

Why self.id = Random? Wouldn't be a timestamp + random a better solution?

class Whitelabel
  extend ActiveModel::Naming
  extend ActiveModel::Callbacks

  include ActiveModel::Model
  include ActiveModel::Validations
  include ActiveModel::Conversion
  include ActionView::Helpers::SanitizeHelper
  include Paperclip::Glue

  define_model_callbacks :save
  define_model_callbacks :destroy

  has_attached_file :logo, url: "/system/:hash.:extension", hash_secret: "longSecretString", styles: { thumb: ["300x300#", :jpeg], original: [:jpeg] }
  #validates_attachment_content_type :logo, content_type: /\Aimage\/[svg+xml|jpg]\z/, message: "File format of attachment is invalid. Please attach an image."
  validates_attachment :logo, presence: true, content_type: { content_type: ["image/jpg", "image/png", "image/gif"] }
  #validate :no_attachement_errors

  attr_accessor :id, :logo_file_name, :logo_file_size, :logo_content_type, :logo_updated_at

  def initialize(args = { })
    args.each_pair do |k, v|
      self.send("#{k}=", v)
    end
    @id = self.class.next_id
  end

  def update_attributes(args = { })
    args.each_pair do |k, v|
      self.send("#{k}=", v)
    end
  end

  def save
    run_callbacks :save do
    end
  end

  def unscoped
    run_callbacks :unscoped do
    end
  end

  def destroy
    run_callbacks :destroy do
    end
  end

  # Need a differentiating id for each new Importer.
  def self.next_id
    @@id_counter += 1
  end

  # Initialize beginning id to something mildly unique.
  @@id_counter = Time.now.to_i

end

Getting this error

NoMethodError: undefined method `unscoped' for Whitelabel:Class
/Users/admin/.rvm/gems/ruby-2.7.1/gems/paperclip-6.1.0/lib/paperclip/helpers.rb:41:in `each_instance_with_attachment'
/Users/admin/.rvm/gems/ruby-2.7.1/gems/paperclip-6.1.0/lib/tasks/paperclip.rake:66:in `block (4 levels) in <main>'
/Users/admin/.rvm/gems/ruby-2.7.1/gems/paperclip-6.1.0/lib/tasks/paperclip.rake:65:in `each'
/Users/admin/.rvm/gems/ruby-2.7.1/gems/paperclip-6.1.0/lib/tasks/paperclip.rake:65:in `block (3 levels) in <main>'
/Users/admin/.rvm/gems/ruby-2.7.1/gems/rake-13.0.6/exe/rake:27:in `<top (required)>'
/Users/admin/.rvm/gems/ruby-2.7.1/bin/ruby_executable_hooks:22:in `eval'
/Users/admin/.rvm/gems/ruby-2.7.1/bin/ruby_executable_hooks:22:in `<main>'
Tasks: TOP => paperclip:refresh => paperclip:refresh:metadata
(See full trace by running task with --trace)