import crafttweaker.item.IItemStack;

val featherStack = [<animania:blue_peacock_feather>, <animania:white_peacock_feather>, <animania:charcoal_peacock_feather>,
					<animania:opal_peacock_feather>, <animania:peach_peacock_feather>, <animania:purple_peacock_feather>,
					<animania:taupe_peacock_feather>] as IItemStack[];
val feather = <ore:feather>;
feather.removeItems(featherStack);