private static IRequestBase GetRequest(IEnumerable <object> inputs)
        {
            RequestHeader head = null;

            if (OperationContext.Current.IncomingMessageProperties.ContainsKey("autoHeader"))
            {
                head = OperationContext.Current.IncomingMessageProperties["autoHeader"] as RequestHeader;
            }
            if (head.IsInstance())
            {
                return(new HeaderWrapper(head));
            }
            return(inputs.IsNull()
                ? null
                : (from m in inputs where m.Implements(typeof(IRequestBase)) select m as IRequestBase).FirstOrDefault());
        }