code: def get_upload_pipeline(in_fd, out_fd, rate_limit=None,
                          gpg_key=None, lzop=True):
      
      commands = []
      if rate_limit is not None:
          commands.append(PipeViewerRateLimitFilter(rate_limit))
      if lzop:
          commands.append(LZOCompressionFilter())
  
      if gpg_key is not None:
          commands.append(GPGEncryptionFilter(gpg_key))
  
      return Pipeline(commands, in_fd, out_fd)
docs: Create a UNIX pipeline to process a file for uploading.
          (Compress, and optionally encrypt)