encode method
Implementation
String? encode() {
switch (this) {
case FrequencyUnit.MONTH:
return 'MONTH';
case FrequencyUnit.WEEK:
return 'WEEK';
case FrequencyUnit.DAY:
return 'DAY';
case FrequencyUnit.HOUR:
return 'HOUR';
case FrequencyUnit.MINUTE:
return 'MINUTE';
case FrequencyUnit.UNKNOWN:
return null;
}
}