code: def get_key(self, key_name, headers=None, version_id=None,
                                              key_type=Key.KEY_REGULAR_FILE):
          
          if key_name == '-':
              return Key(self.name, '-', key_type=Key.KEY_STREAM_READABLE)
          else:
              fp = open(key_name, 'rb')
              return Key(self.name, key_name, fp)
docs: Check to see if a particular key exists within the bucket.
          Returns: An instance of a Key object or None
  
          :type key_name: string
          :param key_name: The name of the key to retrieve
  
          :type version_id: string
          :param version_id: Unused in this subclass.
  
          :type stream_type: integer
          :param stream_type: Type of the Key - Regular File or input/output Stream
  
          :rtype: :class:`boto.file.key.Key`
          :returns: A Key object from this bucket.