Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@monai/transforms/io/array.py`:
- Around line 212-217: The try/except currently only wraps string-based reader
imports but not explicit reader classes, causing OptionalImportError to leak
when someone passes a class like ITKReader to LoadImage; update the code path in
LoadImage where the reader is instantiated (the branch handling the `reader`
argument and any use of `_r`/`reader` to create reader instances) to catch
OptionalImportError around the instantiation and re-raise the same RuntimeError
message used for string readers so both `LoadImage(reader="ITKReader")` and
`LoadImage(reader=ITKReader)` produce the consistent RuntimeError; ensure you
reference the same message and `from e` chaining when catching
OptionalImportError raised during explicit class construction.

In `@tests/transforms/test_load_image.py`:
- Around line 503-529: Add a unit test in TestLoadImageMissingReader to cover
the reader-as-class path: mimic the existing string-case test by patching
ITKReader.__init__ to raise monai.utils.OptionalImportError("itk") and assert
that LoadImage(reader=ITKReader) raises a RuntimeError containing "ITKReader"
and "not installed"; also add the complementary case to ensure
LoadImage(reader=NibabelReader) still succeeds when passing the class object
(assert instance), referencing the LoadImage, ITKReader, and NibabelReader
symbols so the class-based reader API is exercised alongside the string-based
tests.
- Around line 519-523: The test test_unspecified_reader_falls_back_silently
currently only constructs LoadImage() and may pass in CI when optional deps
exist; change it to force the "missing optional readers" path by temporarily
simulating ImportError(s) for the reader modules LoadImage tries to import
(e.g., patch importlib.import_module or the specific module lookup used inside
LoadImage to raise ImportError for PIL/torchvision/imageio), then instantiate
LoadImage() and assert it returns an instance without raising; restore the
original import behavior afterward and optionally assert the warn-and-skip
logging was invoked to prove the fallback path was exercised.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@tests/transforms/test_load_image.py`:
- Around line 538-558: The test is patching SUPPORTED_READERS with the wrong key
("itk") so the fallback path in LoadImage isn't exercised; change the test to
use the actual key used in SUPPORTED_READERS ("itkreader") when saving
original_itk, replacing it with failing_reader (that raises
OptionalImportError), and restoring original_itk afterwards; ensure you still
capture logs with self.assertLogs("LoadImage", level="DEBUG") so the
warn-and-skip behavior is asserted, referencing SUPPORTED_READERS, LoadImage,
failing_reader, and OptionalImportError to locate the relevant lines to update.

---

Nitpick comments:
In `@monai/transforms/io/array.py`:
- Around line 212-220: The TypeError except block in monai.transforms.io.array
(the except handling where it warns that "{_r} is not supported with the given
parameters {args} {kwargs}" and then calls self.register(the_reader())) should
include stacklevel=2 on the warnings.warn call to point the warning at the
caller; update the warnings.warn invocation to pass stacklevel=2 while keeping
the existing message and the subsequent self.register(the_reader()) behavior
unchanged.

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@monai/transforms/io/array.py`:
- Around line 246-248: The warning in the reader-registration block uses a fixed
stacklevel=2 which misattributes the call when LoadImaged.register() delegates
to self._loader.register(); update the registration API and implementation so
register() can accept an optional stacklevel or caller_depth parameter and pass
that through from LoadImaged.register() into the reader-check (the block that
does "if not isinstance(reader, ImageReader): warnings.warn(...,
stacklevel=...)"), or compute the correct stacklevel dynamically (e.g., via
inspect) to skip internal frames; change the relevant symbols LoadImage.register
/ LoadImaged.register / self._loader.register and the reader check in array.py
to propagate or compute the correct stacklevel so the warning points to the
actual user code.

In `@tests/transforms/test_load_image.py`:
- Around line 526-558: Remove the redundant local import of OptionalImportError
inside test_unspecified_reader_falls_back_silently; instead reuse the
module-level OptionalImportError already imported, so delete the line "from
monai.utils import OptionalImportError" in the test, leaving the rest of the
test (including use of SUPPORTED_READERS and LoadImage) unchanged.

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@tests/transforms/test_load_image.py`:
- Around line 551-554: The test cleanup currently restores
SUPPORTED_READERS["itkreader"] only when original_itk is not None, which leaves
the test-installed reader in place if the key was absent originally; change the
finally block to remove the test entry when original_itk is None and restore it
when present: check original_itk (from the setup where you saved the initial
value), and if original_itk is None use SUPPORTED_READERS.pop("itkreader", None)
or del SUPPORTED_READERS["itkreader"] to remove the key, otherwise set
SUPPORTED_READERS["itkreader"] = original_itk to restore the original reader
(reference SUPPORTED_READERS and original_itk in your fix).