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()); }