code: func (cr *channelResponse) Endorsers(invocationChain discclient.InvocationChain, f discclient.Filter) (discclient.Endorsers, error) {
  	if cr.err != nil {
  		return nil, cr.err
  	}
  	return f.Filter(cr.peers), nil
  }
docs: // Endorsers returns the response for an endorser query