public override string ToString() { StringBuilder messageBuilder = new StringBuilder(); foreach (KeyValuePair <string, string> kvp in this) { EncodingHelper.AddKeyValueString(messageBuilder, EncodingHelper.UrlEncode(kvp.Key), EncodingHelper.UrlEncode(kvp.Value)); } if (this.ExtraQueryParameter != null) { messageBuilder.Append('&' + this.ExtraQueryParameter); } return(messageBuilder.ToString()); }