Here’s the example:
protected override void ProcessItem(Item item)
{
var injectedList = new List<MultiFieldItem>();
foreach(var attribute in item.NwpItem.Attributes)
{
var multiFieldItem = new MultiFieldItem();
multiFieldItem.Fields.AddOrUpdateValue(NwpBaseProductConstants.NwpGenericLabel, attribute.Name);
multiFieldItem.Fields.AddOrUpdateValue(NwpBaseProductConstants.NwpGenericValue, attribute.Value);
injectedList.Add(multiFieldItem);
}
item.Variant.Fields.AddOrUpdateValue(NwpBaseProductConstants.NwpGenericProperty, injectedList);
_variantService.Update(item.Variant);
}