Extension class for IEnumerable( Of T)

public static class IEnumerableExtensions
    {
        /// 

        /// ForEach extension method for IEnumerable(Of T)
        /// 
        /// The element type of the IEnumerable object
        /// The IEnumerable(Of T) source
        /// The delegate to perform on each element of the IEnumerable(Of T)
        public static void ForEach(this IEnumerable source, Action action)
        {
            if (action == null)
            {
                throw new ArgumentNullException("action");
            }

            foreach (T item in source)
            {
                action(item);
            }
        }

        /// 

        /// Converts an IEnumerable(Of T) to a delimited string
        /// 
        /// The element type of the IEnumerable object
        /// The IEnumerable(Of T) object
        /// The delimiter to be used in the output string
        /// Delimited string representation of the items
        /// Null or empty items are ignored
        public static string ToDelimitedString(this IEnumerable items, string separator)
        {
            if (items == null || items.Count() == 0)
            {
                return string.Empty;
            }

            return string.Join(separator, items.Where(i => i != null && !i.ToString().IsNullOrWhiteSpace()));
        }

        /// 

        /// Converts an IEnumerable(Of T) to a comma-delimited string
        /// 
        /// The element type of the IEnumerable object
        /// The IEnumerable(Of T) object
        /// Comma-delimited string representation of the items
        /// Null or empty items are ignored
        public static string ToSpaceDelimitedString(this IEnumerable items)
        {
            return items.ToDelimitedString(" ");
        }

        /// 

        /// Converts an IEnumerable(Of T) to a space-delimited string
        /// 
        /// The element type of the IEnumerable object
        /// The IEnumerable(Of T) object
        /// Space-delimited string representation of the items
        /// Null or empty items are ignored
        public static string ToCommaDelimitedString(this IEnumerable items)
        {
            return items.ToDelimitedString(",");
        }
    }