code: def Flush(self):
      
      if self._dirty:
        self.Set(self.Schema.SIZE(self.size))
        if self.content_last is not None:
          self.Set(self.Schema.CONTENT_LAST, self.content_last)
  
      # Flushing the cache will write all chunks to the blob store.
      self.chunk_cache.Flush()
      super(AFF4ImageBase, self).Flush()
docs: Sync the chunk cache to storage.