# File lib/s3/bucket.rb, line 149
    def key(key_name, head=false)
      raise 'Key name can not be empty.' if Aws::Utils.blank?(key_name)
      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 = S3::Key.create(self, key_name.to_s)
      end
      key_instance
    end