# File lib/selenium/webdriver/common/keys.rb, line 91
      def self.encode(keys)
        keys.map do |arg|
          case arg
          when Symbol
            Keys[arg]
          when Array
            arg = arg.map { |e| e.kind_of?(Symbol) ? Keys[e] : e }.join
            arg << Keys[:null]

            arg
          else
            arg.to_s
          end
        end
      end