def serialize(self,writer: SerializationWriter) -> None:
        """
        Serializes information the current object
        param writer: Serialization writer to use to serialize this model
        Returns: None
        """
        if writer is None:
            raise TypeError("writer cannot be null.")
        super().serialize(writer)
        writer.write_timedelta_value("callDuration", self.call_duration)
        writer.write_enum_value("callEventType", self.call_event_type)
        writer.write_str_value("callId", self.call_id)
        writer.write_collection_of_object_values("callParticipants", self.call_participants)
        writer.write_object_value("initiator", self.initiator)

        Serializes information the current object
        param writer: Serialization writer to use to serialize this model
        Returns: None
        
msgraph/generated/models/call_ended_event_message_detail.py