chroottar.py: don't raise NotImplementedError for misuse

The mode actually can only have these three distinct literals. While
more complex modes can get passed to TarFile.open, they're decomposed
there and only of these three is passed to the compressor openers.

1 files changed, 1 insertions, 1 deletions

diff --git a/examples/chroottar.py b/examples/chroottar.py
index 49d9a7d..b210649 100755
--- a/examples/chroottar.py
+++ b/examples/chroottar.py
@@ -34,7 +34,7 @@ class TarFile(tarfile.TarFile):
         fileobj: typing.BinaryIO | None = None,
     ) -> tarfile.TarFile:
         if mode not in ("r", "w", "x"):
-            raise NotImplementedError(f"mode `{mode}' not implemented for zst")
+            raise ValueError("mode must be 'r', 'w' or 'x'")
         openobj: str | typing.BinaryIO = name if fileobj is None else fileobj
         try:
             import zstandard