public AbstractItem(string name, string author, DateTime printDate, EAN ean, string location, int copies)
{
this.Name = name;
this.PrintDate = printDate;
this.Copies = copies;
this.EANNUmber = ean;
this.Location = location;
this.Author = author;
}
public AbstractItem(string name, string author, DateTime printDate, EAN ean, string location) : this(name, author, printDate, ean, location, 1)
{
}