public virtual Teacher Convert(KLehrer source)
        {
            if (source == null)
            {
                return(null);
            }

            return(new Teacher
            {
                Id = source.Id,
                Acronym = source.Kuerzel,
                Firstname = source.Vorname,
                Lastname = source.Nachname,
                Title = source.Titel,
                Gender = GenderConverter.Convert(source.Geschlecht),
                Email = source.EmailDienstlich,
                SectionData = source.Abschnittsdaten?.Select(x => TeacherDataConverter.Convert(x)).ToArray(),
                IsVisible = sichtbarBooleanConverter.Convert(source.Sichtbar)
            });
        }