code: def _get_key_internal(self, *args, **kwargs):
          
          if args[1] is not None and 'force' in args[1]:
              key, res = super(Bucket, self)._get_key_internal(*args, **kwargs)
  
              if key:
                  mimicdb.backend.sadd(tpl.bucket % self.name, key.name)
                  mimicdb.backend.hmset(tpl.key % (self.name, key.name),
                                      dict(size=key.size,
                                           md5=key.etag.strip('"')))
              return key, res
  
          key = None
  
          if mimicdb.backend.sismember(tpl.bucket % self.name, args[0]):
              key = Key(self)
              key.name = args[0]
  
          return key, None
docs: Return None if key is not in the bucket set.
  
          Pass 'force' in the headers to check S3 for the key, and after fetching
          the key from S3, save the metadata and key to the bucket set.