code: def _send_file_internal(self, *args, **kwargs):
          
          super(Key, self)._send_file_internal(*args, **kwargs)
  
          mimicdb.backend.sadd(tpl.bucket % self.bucket.name, self.name)
          mimicdb.backend.hmset(tpl.key % (self.bucket.name, self.name),
                              dict(size=self.size, md5=self.md5))
docs: Called internally for any type of upload. After upload finishes,
          make sure the key is in the bucket set and save the metadata.