def test_split_existing(self):
td = tempfile.mkdtemp()
try:
assert Nested._split_existing(td) == (td, '.')
assert Nested._split_existing(td + os.sep) == (td, '.')
assert Nested._split_existing(os.path.join(td, 'a', 'b', 'c')) == (
td, os.path.join('a', 'b', 'c'))
assert Nested._split_existing(os.path.join(td, 'a', '..', 'c')) == (td, 'c')
finally:
safe_rmtree(td)
