public async Task FillEmailBody_Test()
        {
            var emailServiceMock        = new Mock <IEmailService>().Object;
            var concreteMailServiceMock = new Mock <IConcreteMailService>().Object;
            var searchServiceMock       = new Mock <ISearchService>().Object;
            var encodeDecodeServiceMock = new Mock <IEncodeDecodeService>().Object;

            var    emailData       = "1 TestGmailId";
            string setInvalidEmail = null;

            var defaultContext = new DefaultHttpContext()
            {
                User = new ClaimsPrincipal()
            };

            var controller = new EmailController(emailServiceMock, concreteMailServiceMock,
                                                 searchServiceMock, encodeDecodeServiceMock)
            {
                ControllerContext = new ControllerContext()
                {
                    HttpContext = defaultContext
                }
            };

            var result = await controller.FillEmailBody(emailData, setInvalidEmail);

            Assert.IsInstanceOfType(result, typeof(JsonResult));
        }