code: func (tx *Tx) CopyFrom(r io.Reader, query interface{}, params ...interface{}) (res Result, err error) {
  	err = tx.withConn(context.TODO(), func(cn *pool.Conn) error {
  		res, err = tx.db.copyFrom(cn, r, query, params...)
  		return err
  	})
  	return res, err
  }
docs: // CopyFrom is an alias for DB.CopyFrom.