# File lib/s3/right_s3.rb, line 251
      def key(key_name, head=false)
        raise 'Key name can not be empty.' if key_name.blank?
        key_instance = nil
          # if this key exists - find it ....
        keys({'prefix'=>key_name}, head).each do |key|
          if key.name == key_name.to_s
            key_instance = key
            break
          end
        end
          # .... else this key is unknown
        unless key_instance
          key_instance = Key.create(self, key_name.to_s)
        end
        key_instance
      end