public void CheckSaAltAllele()
{
var customItem = new CustomItem("chr1", 100, "ATATA", "TTT", "test", "cust101", true, null, null);
var spc = new SupplementaryPositionCreator(new SupplementaryAnnotationPosition(100));
customItem.SetSupplementaryAnnotations(spc);
Assert.Equal("5TTT", spc.SaPosition.CustomItems[0].SaAltAllele);
}