code: func (c *connection) Offset(req *proto.OffsetReq) (*proto.OffsetResp, error) {
  	// TODO(husio) documentation is not mentioning this directly, but I assume
  	// -1 is for non node clients
  	req.ReplicaID = -1
  
  	b, err := c.sendRequest(req)
  	if err != nil {
  		return nil, err
  	}
  	return proto.ReadVersionedOffsetResp(bytes.NewReader(b), req.GetVersion())
  }
docs: // Offset sends given offset request to kafka node and returns related response.
  // Calling this method on closed connection will always return ErrClosed.