public ListingFees RetrieveFeesForCategory(string categoryNumber)
{
var url = String.Format(Constants.Culture, "{0}/{1}/{2}{3}", Constants.CATEGORIES, categoryNumber,
Constants.FEES, Constants.XML);
var getRequest = _connection.UnauthenticatedConnection(url);
var xml = getRequest.ToString();
return Deserializer<ListingFees>.Deserialize(new ListingFees(), xml);
}