public void WalkUp_RelativePath_Exists1()
{
// arrange
var dir = new DirectoryEx(".\\Sample")
.GetNestedDirectory("KSW Doradztwo\\2018\\\\PZ Solutions\\2018");
// act
var results = dir.WalkUp().ToArray();
// assert
results.Should().HaveCount(3);
results[0].Name.Should().Be("2018");
results[1].Name.Should().Be("PZ Solutions");
results[2].Name.Should().Be($"{Path.DirectorySeparatorChar}");
}