/// <summary>
        /// Excels to subject.
        /// </summary>
        /// <param name="subjects">The subjects.</param>
        /// <param name="rows">The rows.</param>
        public static Subject ExcelToSubject(DataRow row)
        {
            Subject subject = new Subject();

            subject.Nachname  = row[ExcelExtension.GetExcelColumnName(() => subject.Nachname)].ToString().ToNullableString();
            subject.Vorname   = row[ExcelExtension.GetExcelColumnName(() => subject.Vorname)].ToString().ToNullableString();
            subject.T1        = row[ExcelExtension.GetExcelColumnName(() => subject.T1)].ToString().ToNullable <int>();
            subject.T2        = row[ExcelExtension.GetExcelColumnName(() => subject.T2)].ToString().ToNullable <int>();
            subject.T3        = row[ExcelExtension.GetExcelColumnName(() => subject.T3)].ToString().ToNullable <int>();
            subject.T4        = row[ExcelExtension.GetExcelColumnName(() => subject.T4)].ToString().ToNullable <int>();
            subject.T5        = row[ExcelExtension.GetExcelColumnName(() => subject.T5)].ToString().ToNullable <int>();
            subject.T6        = row[ExcelExtension.GetExcelColumnName(() => subject.T6)].ToString().ToNullable <int>();
            subject.T7        = row[ExcelExtension.GetExcelColumnName(() => subject.T7)].ToString().ToNullable <int>();
            subject.T8        = row[ExcelExtension.GetExcelColumnName(() => subject.T8)].ToString().ToNullable <int>();
            subject.T9        = row[ExcelExtension.GetExcelColumnName(() => subject.T9)].ToString().ToNullable <int>();
            subject.T10       = row[ExcelExtension.GetExcelColumnName(() => subject.T10)].ToString().ToNullable <int>();
            subject.MwT       = row[ExcelExtension.GetExcelColumnName(() => subject.MwT)].ToString().ToNullable <double>().RoundNullableDouble();
            subject.K1        = row[ExcelExtension.GetExcelColumnName(() => subject.K1)].ToString().ToNullable <int>();
            subject.K2        = row[ExcelExtension.GetExcelColumnName(() => subject.K2)].ToString().ToNullable <int>();
            subject.K3        = row[ExcelExtension.GetExcelColumnName(() => subject.K3)].ToString().ToNullable <int>();
            subject.K4        = row[ExcelExtension.GetExcelColumnName(() => subject.K4)].ToString().ToNullable <int>();
            subject.MwK       = row[ExcelExtension.GetExcelColumnName(() => subject.MwK)].ToString().ToNullable <double>().RoundNullableDouble();
            subject.AktN      = row[ExcelExtension.GetExcelColumnName(() => subject.AktN)].ToString().ToNullable <double>().RoundNullableDouble();
            subject.Hj        = row[ExcelExtension.GetExcelColumnName(() => subject.Hj)].ToString().ToNullable <int>();
            subject.Ej        = row[ExcelExtension.GetExcelColumnName(() => subject.Ej)].ToString().ToNullable <int>();
            subject.Kommentar = row[ExcelExtension.GetExcelColumnName(() => subject.Kommentar)].ToString().ToNullableString();

            return(subject);
        }
        /// <summary>
        /// Excels to teacher.
        /// </summary>
        /// <param name="teachers">The teachers.</param>
        /// <param name="rows">The rows.</param>
        public static Teacher ExcelToTeacher(DataRow row)
        {
            Teacher teacher = new Teacher();

            teacher.Nachname      = row[ExcelExtension.GetExcelColumnName(() => teacher.Nachname)].ToString().ToNullableString();
            teacher.Vorname       = row[ExcelExtension.GetExcelColumnName(() => teacher.Vorname)].ToString().ToNullableString();
            teacher.Anrede        = row[ExcelExtension.GetExcelColumnName(() => teacher.Anrede)].ToString().ToNullableString();
            teacher.Fach          = row[ExcelExtension.GetExcelColumnName(() => teacher.Fach)].ToString().ToNullableString();
            teacher.Klassenleiter = row[ExcelExtension.GetExcelColumnName(() => teacher.Klassenleiter)].ToString().KlassenleiterToBool();
            teacher.Kuerzel       = row[ExcelExtension.GetExcelColumnName(() => teacher.Kuerzel)].ToString().ToNullableString();

            return(teacher);
        }
        /// <summary>
        /// Excels to total.
        /// </summary>
        /// <param name="totals">The totals.</param>
        /// <param name="rows">The rows.</param>
        public static Total ExcelToTotal(DataRow row)
        {
            Total total = new Total();

            total.Vorname   = row[ExcelExtension.GetExcelColumnName(() => total.Vorname)].ToString().ToNullableString();
            total.Nachname  = row[ExcelExtension.GetExcelColumnName(() => total.Nachname)].ToString().ToNullableString();
            total.Deutsch   = row[ExcelExtension.GetExcelColumnName(() => total.Deutsch)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Mathe     = row[ExcelExtension.GetExcelColumnName(() => total.Mathe)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Sachkunde = row[ExcelExtension.GetExcelColumnName(() => total.Sachkunde)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Musik     = row[ExcelExtension.GetExcelColumnName(() => total.Musik)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Englisch  = row[ExcelExtension.GetExcelColumnName(() => total.Englisch)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Ethik     = row[ExcelExtension.GetExcelColumnName(() => total.Ethik)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Kunst     = row[ExcelExtension.GetExcelColumnName(() => total.Kunst)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Sport     = row[ExcelExtension.GetExcelColumnName(() => total.Sport)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Religion  = row[ExcelExtension.GetExcelColumnName(() => total.Religion)].ToString().ToNullable <double>().RoundNullableDouble();
            total.Werken    = row[ExcelExtension.GetExcelColumnName(() => total.Werken)].ToString().ToNullable <double>().RoundNullableDouble();
            total.MwS       = row[ExcelExtension.GetExcelColumnName(() => total.MwS)].ToString().ToNullable <double>().RoundNullableDouble();

            return(total);
        }