public void ValidateEnumerableHaveCountOf()
        {
            // Given
            var validator = new EnumerableValidator <int>(new List <int> {
                1
            });

            // When
            validator.HaveCountOf(1);

            // Then
            Assert.True(true);
        }
        public void ValidateEnumerableHaveCountOfViolated()
        {
            // Given
            var validator = new EnumerableValidator <int>(new List <int> {
                1
            });

            // When
            var exception = Assert.Throws <XunitException>(() => validator.HaveCountOf(0, "that's the bottom line"));

            // Then
            Assert.NotNull(exception);
            var rn = Environment.NewLine;

            Assert.Equal(
                $"{rn}validator{rn}contains \"1\" item(s){rn}but was expected to have \"0\" item(s){rn}because that's the bottom line",
                exception.UserMessage);
        }