func (r *msgReader) Err() error {
	return r.err
}
Err returns any error that the msgReader has experienced
package pgx
import (
	"bufio"
	"encoding/binary"
	"errors"
	"io"
)
type msgReader struct {
	reader            *bufio.Reader
	buf               [128]byte
	msgBytesRemaining int32
	err               error
	log               func(lvl int, msg string, ctx ...interface{})
	shouldLog         func(lvl int) bool
}