public void ValidateContents_CallsAppropriateMethods()
        {
            // Arrange
            var contents = fixture.Create <string>();

            // Act
            _sut.ValidateContents(contents);

            // Assert
            _parserServiceMock.Verify(s => s.ValidateCount(It.Is <string>(x => x == contents)), Times.Once);
            _parserServiceMock.Verify(s => s.ValidateNesting(It.Is <string>(x => x == contents)), Times.Once);
        }