code: def Run(self, args):
      
      # Make sure we limit the size of our output
      if args.length > constants.CLIENT_MAX_BUFFER_SIZE:
        raise RuntimeError("Can not read buffers this large.")
  
      try:
        fd = vfs.VFSOpen(args.pathspec, progress_callback=self.Progress)
  
        fd.Seek(args.offset)
        offset = fd.Tell()
  
        data = fd.Read(args.length)
  
      except (IOError, OSError) as e:
        self.SetStatus(rdf_flows.GrrStatus.ReturnedStatus.IOERROR, e)
        return
  
      # Now return the data to the server
      self.SendReply(
          rdf_client.BufferReference(
              offset=offset, data=data, length=len(data), pathspec=fd.pathspec))
docs: Reads a buffer on the client and sends it to the server.