```ruby
require "espinita/engine"
require "request_store"

module Espinita

  autoload :Auditor, "espinita/auditor"
  autoload :AuditorBehavior, "espinita/auditor_behavior"
  autoload :AuditorRequest, "espinita/auditor_request"

  class << self

    attr_accessor :current_user_method
   
    def current_user_method
      @current_user_method ||= :current_user
    end

  end

  def self.rails51? # :nodoc:
    Rails.gem_version >= Gem::Version.new("5.1.x")
  end

end
```

Add rails version check method
user
```ruby
require "espinita/engine"
require "request_store"

module Espinita

  autoload :Auditor, "espinita/auditor"
  autoload :AuditorBehavior, "espinita/auditor_behavior"
  autoload :AuditorRequest, "espinita/auditor_request"

  class << self

    attr_accessor :current_user_method
   
    def current_user_method
      @current_user_method ||= :current_user
    end

  end

  def self.rails51?
    Rails.version.start_with? '5.1'
  end

end
```
assistant