minor fix

Signed-off-by: Alexandros Koumparoulis <akoumparouli@nvidia.com>

nemo/lightning/pytorch/callbacks/memory_profiler.py

@@ -44,6 +44,7 @@ def __init__(self, dir: str = "/mem_profile", warn_cycles=True, ranks=[], interv
 
         self.dir = dir
         self.ranks = ranks
+        assert isinstance(self.interval, int), "Expected interval to be an integer"
         self.interval = interval
         self.step = 0
 
@@ -87,7 +88,7 @@ def _dump_memory_snapshot(self, _snapshot_path=None, rank=None):
 
     def on_train_batch_start(self, trainer, pl_module, batch, batch_idx, unused=0) -> None:
         # It's disabled
-        if self.interval is None or self.interval <= 0:
+        if self.interval <= 0:
             return
         if self.step % self.interval == 0:
             if self.enable_on_rank():