public static int IndexOf <T>([NotNull] this IEnumerable <T> collection, [NotNull] T item, [NotNull] IEqualityComparer <T> comparer)
{
collection = collection.ArgumentItemsExists();
item = item.ArgumentNotNull();
comparer = comparer.ArgumentNotNull();
return(collection.Select((x, index) => comparer.Equals(item, x) ? index : -1).FirstOrDefault(x => x != -1, -1));
}
