public async Task Validate_ReturnsFalse_When_ValueLengthIsLessThenMinLength()
        {
            string value = "a";
            IStringValidator_OLD validator = new LoginValidator_OLD(value.Length + 1, value.Length + 2);

            Assert.IsFalse(await validator.ValidateAsync(value));
        }
        public async Task Validate_ReturnsFalse_When_ValueLengthIsGreaterThenMaxLength()
        {
            string value = "abc";
            IStringValidator_OLD validator = new LoginValidator_OLD(value.Length - 2, value.Length - 1);

            Assert.IsFalse(await validator.ValidateAsync(value));
        }
        public async Task Validate_ReturnsTrue_When_ValueLengthIsEqualsMinAndMaxLength()
        {
            string value = "a";
            IStringValidator_OLD validator = new LoginValidator_OLD(value.Length, value.Length);

            Assert.IsTrue(await validator.ValidateAsync(value));
        }
        public async Task Validate_ReturnsFalse_When_ValueIsEmpty()
        {
            IStringValidator_OLD validator = new LoginValidator_OLD(1, 2);

            Assert.IsFalse(await validator.ValidateAsync(string.Empty));
        }