public async void Test_LessThanDoubleChecker()
        {
            var checker = new LessThanDoubleChecker<Student>(5d, _Validation);

            var result = await checker.ValidateAsync(new ValidateResult(), 3d, "", "");
            Assert.True(result.IsValid);

            result = await checker.ValidateAsync(new ValidateResult(), 7d, "a", null);
            Assert.False(result.IsValid);
            Assert.Equal(1, result.Failures.Count);
            Assert.Equal("a", result.Failures[0].Name);
            Assert.Equal(string.Format("The value must less than {0}", 5d), result.Failures[0].Error);
            Assert.Equal(7d, result.Failures[0].Value);

            result = await checker.ValidateAsync(new ValidateResult(), 5d, "a1", "c");
            Assert.False(result.IsValid);
            Assert.Equal(1, result.Failures.Count);
            Assert.Equal("a1", result.Failures[0].Name);
            Assert.Equal("c", result.Failures[0].Error);
            Assert.Equal(5d, result.Failures[0].Value);
        }
        public async void Test_LessThanDoubleChecker()
        {
            var checker = new LessThanDoubleChecker <Student>(5d, _Validation);

            var result = await checker.ValidateAsync(new ValidateResult(), 3d, "", "");

            Assert.True(result.IsValid);

            result = await checker.ValidateAsync(new ValidateResult(), 7d, "a", null);

            Assert.False(result.IsValid);
            Assert.Equal(1, result.Failures.Count);
            Assert.Equal("a", result.Failures[0].Name);
            Assert.Equal(string.Format("The value must less than {0}", 5d), result.Failures[0].Error);
            Assert.Equal(7d, result.Failures[0].Value);

            result = await checker.ValidateAsync(new ValidateResult(), 5d, "a1", "c");

            Assert.False(result.IsValid);
            Assert.Equal(1, result.Failures.Count);
            Assert.Equal("a1", result.Failures[0].Name);
            Assert.Equal("c", result.Failures[0].Error);
            Assert.Equal(5d, result.Failures[0].Value);
        }