resolve
Adds
relative
file to this, considering this as a directory.
If
relative
has a root,
relative
is returned back.
For instance,
File("/foo/bar").resolve(File("gav"))
is
File("/foo/bar/gav")
.
This function is complementary with
relativeTo
,
so
f.resolve(g.relativeTo(f)) == g
should be always
true
except for different roots case.
Return concatenated this and relative paths, or just relative if it's absolute.