def METHOD_NAME(self):
    testing_dir = os.path.join(os.path.dirname(os.path.realpath(__file__)), "testing_data")
    keys = "image"
    xforms = Compose(
        [
            LoadImaged(keys=keys),
            EnsureChannelFirstd(keys=keys, channel_dim="no_channel"),
            ScaleIntensityd(keys=keys),
        ]
    )
    image_path = os.path.join(testing_dir, "anatomical.nii")
    ims = xforms({keys: image_path})
    fig = pyplot.figure()  # external figure
    fig, _ = matshow3d(ims[keys], fig=fig, figsize=(2, 2), frames_per_row=5, every_n=2, frame_dim=-1, show=False)
    with tempfile.TemporaryDirectory() as tempdir:
        tempimg = f"{tempdir}/matshow3d_test.png"
        fig.savefig(tempimg)
        comp = compare_images(f"{testing_dir}/matshow3d_test.png", tempimg, 5e-2)
        self.assertIsNone(comp, f"value of comp={comp}")  # None indicates test passed
    _, axes = pyplot.subplots()
    matshow3d(ims[keys], fig=axes, figsize=(2, 2), frames_per_row=5, every_n=2, frame_dim=-1, show=False)