Resolving Dataset and OneOf test fails

Signed-off-by: Ben Murray <[email protected]>

monai/data/dataset.py

@@ -95,7 +95,7 @@ def _transform(self, index: int):
         Fetch single data item from `self.data`.
         """
         data_i = self.data[index]
-        return apply_transform(self.transform, data_i) if self.transform is not None else data_i
+        return self.transform(data_i) if self.transform is not None else data_i
 
     def __getitem__(self, index: int | slice | Sequence[int]):
         """

monai/transforms/compose.py

@@ -569,6 +569,10 @@ def _normalize_probabilities(self, weights):
         weights = weights / weights.sum()
         return list(weights)
 
+    def __len__(self):
+        """Return number of transformations."""
+        return len(tuple(transform_iterator(self, step_into_all=True)))
+
     def flatten(self):
         transforms = []
         weights = []