code: func (c *SessionContext) Close() error {
  	closers := c.TransferClosers()
  	for _, closer := range closers {
  		c.Debugf("Closing %v.", closer)
  		closer.Close()
  	}
  	if c.clt != nil {
  		return trace.Wrap(c.clt.Close())
  	}
  	return nil
  }
docs: // Close cleans up connections associated with requests