[Modify] Polish it

websocket-sharp/Net/HttpListenerPrefixCollection.cs

@@ -51,8 +51,7 @@ namespace WebSocketSharp.Net
   /// The <see cref="HttpListener"/> instance responds to the request which has
   /// a requested URI that the prefixes most closely match.
   /// </remarks>
-  public class HttpListenerPrefixCollection
+  public class HttpListenerPrefixCollection : ICollection<string>
-    : ICollection<string>, IEnumerable<string>, IEnumerable
   {
     #region Private Fields