Provider Pattern

using System;
using System.Configuration;
using System.Configuration.Provider;

namespace Cli.Lsp.Provider.CurrencyProvider {
    public class WSCurrencyConversion : CurrencyProviderBase {
        private String url;

        public String URL {
            get { return url; }
            set { url = value; }
            }


        public override void Initialize(string name, System.Collections.Specialized.NameValueCollection config) {
            #region Attributes check
            if ((config == null) || (config.Count == 0))
                throw new ArgumentNullException("You must supply a valid configuration parameters.");
            this._name = name;
            #endregion

            #region Description
            if (string.IsNullOrEmpty(config["description"])) {
                throw new ProviderException("You must specify a description attribute.");
                }
            this._description = config["description"];
            config.Remove("description");
            #endregion

            #region URL
            if (String.IsNullOrEmpty(config["url"]))
                throw new ProviderException("The url is invalid.");
            this.url = config["url"];
            config.Remove("url");
            #endregion

            #region Extra Attributes validations
            if (config.Count > 0) {
                string extraAttribute = config.GetKey(0);
                if (!String.IsNullOrEmpty(extraAttribute))
                    throw new ProviderException("The following unrecognized attribute was found in " + Name + "'s configuration: '" +
                                                extraAttribute + "'");
                else
                    throw new ProviderException("An unrecognized attribute was found in the provider's configuration.");
                }
            #endregion
            }

        public override decimal Convert(Currency cur, decimal value) {
            Console.WriteLine("---- Convert method was Invoked SQL Currency conversion ----");
            Console.WriteLine("Provider Description ={0}", this.Description);
            Console.WriteLine("URL ={0}", this.URL);
            Console.WriteLine("Convert({0},{1}) ", Enum.GetName(typeof(Currency), cur), value);
            Console.ReadLine();
            return 3.4m;
            }

        public override void Add(Currency cur, DateTime date, decimal factor) {
            Console.WriteLine("---- Add method was Invoked SQL Currency conversion ----");
            Console.WriteLine("Provider Description ={0}", this.Description);
            Console.WriteLine("URL ={0}", this.URL);            
            Console.WriteLine("Add({0},{1},{2}) ", Enum.GetName(typeof(Currency), cur), date, factor);
            Console.ReadLine();
            }

        public override void Remove(Currency cur, DateTime date) {
            Console.WriteLine("---- Remove method was Invoked SQL Currency conversion ----");
            Console.WriteLine("Provider Description ={0}", this.Description);
            Console.WriteLine("URL ={0}", this.URL);            
            Console.WriteLine("Remove({0},{1}) ", Enum.GetName(typeof(Currency), cur), date);
            Console.ReadLine();
            }


        public override CurrencyConversionItem[] List(Currency cur, DateTime startDate, DateTime endDate) {
            Console.WriteLine("---- List method was Invoked SQL Currency conversion ----");
            Console.WriteLine("Provider Description ={0}", this.Description);
            Console.WriteLine("URL ={0}", this.URL);            
            Console.WriteLine("List({0},{1},{2}) ", Enum.GetName(typeof(Currency), cur), startDate, endDate);
            Console.ReadLine();
            return new CurrencyConversionItem[0];
            }
        }
    }