if defined? ::BasicObject
  # A class with no predefined methods that behaves similarly to Builder's
  # BlankSlate. Used for proxy classes.
  class BasicObject < ::BasicObject
    begin
      undef_method :==
      undef_method :equal?
    rescue
    end

    # Let ActiveSupport::BasicObject at least raise exceptions.
    def raise(*args)
      ::Object.send(:raise, *args)
    end
  end
else
  class BasicObject #:nodoc:
    instance_methods.each do |m|
      undef_method(m) if m.to_s !~ /(?:^__|^nil\?$|^send$|^object_id$)/
    end
  end
end