public static ResponseEnvelope <T> CreateErrorResponseEnvelope <T>(ValidationErrorMessage message, T content = default(T))
        {
            var response = new ResponseEnvelope <T>
            {
                Content = content,
                Success = false,
                Error   = message,
            };

            return(response);
        }
        public static ResponseEnvelope <T> CreateResponseEnvelope <T>(T content, ValidationMessage?message = null)
        {
            var response = new ResponseEnvelope <T>
            {
                Content = content,
                Success = true,
                Message = message ?? ValidationMessageHelper.Create(ValidationMessages.SUCCESS)
            };

            return(response);
        }