}

	duration := ts2.Sub(ts1)
	y1, m1, d1 := ts1.Date()
	y2, m2, d2 := ts2.Date()

	switch timePart {
	case timePartYear:
		dy := int64(y2 - y1)
		if m2 > m1 || (m2 == m1 && d2 >= d1) {
			return FromInt(dy), nil
		}
		return FromInt(dy - 1), nil
	case timePartMonth:
		m1 += time.Month(12 * y1)
		m2 += time.Month(12 * y2)

		return FromInt(int64(m2 - m1)), nil
	case timePartDay:

func GetInternalReplicationState(m map[string][]byte) ReplicationState {
	m1 := make(map[string]string, len(m))
	for k, v := range m {
		m1[k] = string(v)
	}
	return getInternalReplicationState(m1)
}

// getInternalReplicationState fetches internal replication state from the map m
func getInternalReplicationState(m map[string]string) ReplicationState {