/// <summary>
 /// <para>Sell similar from an existing or expired auction or classified. 
 /// Creates a new listing without modifying editable fields.Relist an item that has expired. 
 /// Relists an item without modifying editable fields.
 /// </para><para>
 /// Sell similar from an existing or expired auction or classified. 
 /// Creates a new listing without modifying editable fields.
 /// </para>
 /// REQUIRES AUTHENTICATION.
 /// </summary>
 /// <param name="request">The object that will be serialized into xml and then sent in a POST message.</param>
 /// <returns>XDocument: ListingResponse</returns>
 public XDocument SellSimilarItem(SellSimilarListingRequest request)
 {
     var query = String.Format(Constants.Culture, "{0}/{1}{2}", Constants.SELLING, Constants.SIMILAR, Constants.XML);
     return _connection.Post(request, query);
 }
        /// <summary>
        /// <para>Sell similar from an existing or expired auction or classified. 
        /// Creates a new listing without modifying editable fields.Relist an item that has expired. 
        /// Relists an item without modifying editable fields.
        /// </para><para>
        /// Sell similar from an existing or expired auction or classified. 
        /// Creates a new listing without modifying editable fields.
        /// </para>
        /// REQUIRES AUTHENTICATION.
        /// </summary>
        /// <param name="request">The object that will be serialized into xml and then sent in a POST message.</param>
        /// <returns>XDocument: ListingResponse</returns>
        public XDocument SellSimilarItem(SellSimilarListingRequest request)
        {
            if (_selling == null)
            {
                _selling = new SellingMethods(_connection);
            }

            return _selling.SellSimilarItem(request);
        }