public static OffsetDateTime timestampOfEpochNano(long epochNano) {
        Instant instantNanoTimestamp = Instant.ofEpochSecond( 0, epochNano );
        return OffsetDateTime.ofInstant(instantNanoTimestamp, ZoneOffset.UTC);
    }
Obtains an instance of OffsetDateTime using nanoseconds from the epoch
@param epochNano the number of nanoseconds from epoch
@return the offset date-time, not null
src/main/java/org/replicadb/time/Conversions.java