code: func (whisper *Whisper) AllowP2PMessagesFromPeer(peerID []byte) error {
  	p, err := whisper.getPeer(peerID)
  	if err != nil {
  		return err
  	}
  	p.trusted = true
  	return nil
  }
docs: // AllowP2PMessagesFromPeer marks specific peer trusted,
  // which will allow it to send historic (expired) messages.