# File lib/picnic.rb, line 82
      def authenticate_using(mod)
        require 'picnic/authentication'
        mod = "#{self}::Authentication::#{mod.to_s.camelize}".constantize unless mod.kind_of? Module
        
        $LOG.info("Enabling authentication for all requests using #{mod.inspect}.")
        
        module_eval do
          include mod
        end
      end