Untitled

public class PersonManager
{
        MongoSession mongoSession;

        public PersonManager (MongoSession _mongoSession)
        {
                mongoSession = _mongoSession;
        }

        public Person Save (object o)
        {
                Person person;
                try {
                        person = o as Person;
                } catch {
                        throw new Exception ("You can only save an object that inherits Person");
                }

                var personCollection = mongoSession.Database.GetCollection <Person> ("person");
                personCollection.Insert<Person> (person); // I don't want to have to specific Person here...

                return person;
        }
}

class SomeProcess {

        public PersonManager personManager { get; set; }

        public void Process (string ent, object dto)
        {
                var data  = dto as SomeDto;

                // create person
                var complexPerson = Mapper.Map<SomeDto, SomeComplexPerson>(data);
                complexPerson.AddedOn = DateTime.UtcNow;
                personManager.Save (complexPerson);
        }

}