fn write_model<W: Write>(&self, writer: &mut W) -> anyhow::Result<()> {

        use crate::model::property::ComponentProperty;

        match self {

            ComponentProperty::DateTimeStamp(property) => {

                writer.write_all(b"DTSTAMP")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::UniqueIdentifier(property) => {

                writer.write_all(b"UID")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::DateTimeStart(property) => {

                writer.write_all(b"DTSTART")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Classification(property) => {

                writer.write_all(b"CLASS")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::DateTimeCreated(property) => {

                writer.write_all(b"CREATED")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Description(property) => {

                writer.write_all(b"DESCRIPTION")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::GeographicPosition(property) => {

                writer.write_all(b"GEO")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                write!(writer, "{};", property.value.latitude)?;

                write!(writer, "{}", property.value.longitude)?;

            ComponentProperty::LastModified(property) => {

                writer.write_all(b"LAST-MODIFIED")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Location(property) => {

                writer.write_all(b"LOCATION")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Organizer(property) => {

                writer.write_all(b"ORGANIZER")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                writer.write_all(property.value.as_bytes())?;

            ComponentProperty::Priority(property) => {

                writer.write_all(b"PRIORITY")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                write!(writer, "{}", property.value)?;

            ComponentProperty::Sequence(property) => {

                writer.write_all(b"SEQUENCE")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                write!(writer, "{}", property.value)?;

            ComponentProperty::Summary(property) => {

                writer.write_all(b"SUMMARY")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::TimeTransparency(property) => {

                writer.write_all(b"TRANSP")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::RequestStatus(property) => {

                writer.write_all(b"REQUEST-STATUS")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                if let Some(code) = property.value.status_code.first() {

                    write!(writer, "{}", code)?;

                for code in property.value.status_code.iter().skip(1) {

                    write!(writer, ".{}", code)?;

                writer.write_all(b";")?;

                writer.write_all(property.value.description.as_bytes())?;

                if let Some(exception_data) = &property.value.exception_data {

                    writer.write_all(b";")?;

                    writer.write_all(exception_data.as_bytes())?;

            ComponentProperty::Url(property) => {

                writer.write_all(b"URL")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                writer.write_all(property.value.as_bytes())?;

            ComponentProperty::RecurrenceId(property) => {

                writer.write_all(b"RECURRENCE-ID")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::RecurrenceRule(property) => {

                writer.write_all(b"RRULE")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::DateTimeEnd(property) => {

                writer.write_all(b"DTEND")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Duration(property) => {

                writer.write_all(b"DURATION")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Attach(property) => {

                writer.write_all(b"ATTACH")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                writer.write_all(property.value.as_bytes())?;

            ComponentProperty::Attendee(property) => {

                writer.write_all(b"ATTENDEE")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                writer.write_all(property.value.as_bytes())?;

            ComponentProperty::Categories(property) => {

                writer.write_all(b"CATEGORIES")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                if let Some(category) = property.value.first() {

                    category.write_model(writer)?;

                for category in property.value.iter().skip(1) {

                    writer.write_all(b",")?;

                    category.write_model(writer)?;

            ComponentProperty::Comment(property) => {

                writer.write_all(b"COMMENT")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Contact(property) => {

                writer.write_all(b"CONTACT")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::ExceptionDateTimes(property) => {

                writer.write_all(b"EXDATE")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                if let Some(dt) = property.value.first() {

                    dt.write_model(writer)?;

                for dt in property.value.iter().skip(1) {

                    writer.write_all(b",")?;

                    dt.write_model(writer)?;

            ComponentProperty::Status(property) => {

                writer.write_all(b"STATUS")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::RelatedTo(property) => {

                writer.write_all(b"RELATED-TO")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Resources(property) => {

                writer.write_all(b"RESOURCES")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                if let Some(resource) = property.value.first() {

                    resource.write_model(writer)?;

                for resource in property.value.iter().skip(1) {

                    writer.write_all(b",")?;

                    resource.write_model(writer)?;

            ComponentProperty::RecurrenceDateTimes(property) => {

                writer.write_all(b"RDATE")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                match &property.value {

                    RecurrenceDateTimesPropertyValue::DateTimes(date_times) => {

                        if let Some(dt) = date_times.first() {

                            dt.write_model(writer)?;

                        for dt in date_times.iter().skip(1) {

                            writer.write_all(b",")?;

                            dt.write_model(writer)?;

            ComponentProperty::DateTimeCompleted(property) => {

                writer.write_all(b"COMPLETED")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::PercentComplete(property) => {

                writer.write_all(b"PERCENT-COMPLETE")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                write!(writer, "{}", property.value)?;

            ComponentProperty::DateTimeDue(property) => {

                writer.write_all(b"DUE")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::FreeBusyTime(property) => {

                writer.write_all(b"FREEBUSY")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                if let Some(period) = property.value.first() {

                    period.write_model(writer)?;

                for period in property.value.iter().skip(1) {

                    writer.write_all(b",")?;

                    period.write_model(writer)?;

            ComponentProperty::TimeZoneId(property) => {

                writer.write_all(b"TZID")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                if property.value.unique_registry_id {

                }

                writer.write_all(property.value.id.as_bytes())?;

            ComponentProperty::TimeZoneUrl(property) => {

                writer.write_all(b"TZURL")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                writer.write_all(property.value.as_bytes())?;

            ComponentProperty::TimeZoneOffsetTo(property) => {

                writer.write_all(b"TZOFFSETTO")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::TimeZoneOffsetFrom(property) => {

                writer.write_all(b"TZOFFSETFROM")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::TimeZoneName(property) => {

                writer.write_all(b"TZNAME")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Action(property) => {

                writer.write_all(b"ACTION")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                property.value.write_model(writer)?;

            ComponentProperty::Trigger(property) => {

                writer.write_all(b"TRIGGER")?;

                match &property.value {

                    crate::model::property::TriggerValue::Relative(duration) => {

                        property.params.as_slice().write_model(writer)?;

                        writer.write_all(b":")?;

                        duration.write_model(writer)?;

                    crate::model::property::TriggerValue::Absolute(date_time) => {

                        property.params.as_slice().write_model(writer)?;

                        writer.write_all(b":")?;

                        date_time.write_model(writer)?;

            ComponentProperty::Repeat(property) => {

                writer.write_all(b"REPEAT")?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                write!(writer, "{}", property.value)?;

            ComponentProperty::IanaProperty(property) => {

                writer.write_all(property.name.as_bytes())?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                writer.write_all(property.value.as_bytes())?;

            ComponentProperty::XProperty(property) => {

                writer.write_all(property.name.as_bytes())?;

                property.params.as_slice().write_model(writer)?;

                writer.write_all(b":")?;

                writer.write_all(property.value.as_bytes())?;

        Ok(())

    }

    fn write_model<W: Write>(&self, writer: &mut W) -> anyhow::Result<()> {

        for param in self.iter() {

            writer.write_all(b";")?;

            param.write_model(writer)?;

        Ok(())

    }