[2.6] Add rank type check for client API (#3524)

Fixes # .

### Description

Adding #3523

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [ ] New tests added to cover the changes.
- [ ] Quick tests passed locally by running `./runtest.sh`.
- [ ] In-line docstrings updated.
- [ ] Documentation updated.

Author: holgerroth

examples/advanced/bionemo/README.md

@@ -16,7 +16,7 @@ In this repo you will find two notebooks under the `task_fitting` and `downstrea
 Download and run the [BioNeMo docker container](https://catalog.ngc.nvidia.com/orgs/nvidia/teams/clara/containers/bionemo-framework).
 > **Note:** The examples here were tested with `nvcr.io/nvidia/clara/bionemo-framework:2.5`
 
-We recommend following the [User Guide](https://docs.nvidia.com/bionemo-framework/latest/user-guide/)
+We recommend following the [User Guide](https://docs.nvidia.com/bionemo-framework)
 on how to get started with BioNeMo 2.
 
 Start the container and Jupyter Lab to run the NVFlare experiments with NVFlare using

nvflare/client/api.py

@@ -14,7 +14,7 @@
 
 import logging
 from threading import Lock
-from typing import Any, Dict, Optional
+from typing import Any, Dict, Optional, Union
 
 from nvflare.apis.analytix import AnalyticsDataType
 from nvflare.app_common.abstract.fl_model import FLModel
@@ -49,7 +49,7 @@ def get_context(ctx: Optional[APIContext] = None) -> APIContext:
         raise RuntimeError("APIContext is None")
 
 
-def init(rank: Optional[str] = None, config_file: Optional[str] = None) -> APIContext:
+def init(rank: Optional[Union[str, int]] = None, config_file: Optional[str] = None) -> APIContext:
     """Initializes NVFlare Client API environment.
 
     Args:
@@ -60,6 +60,16 @@ def init(rank: Optional[str] = None, config_file: Optional[str] = None) -> APICo
     Returns:
         APIContext
     """
+
+    # subsequent logic assumes rank is a string
+    if rank is not None:
+        if isinstance(rank, int):
+            rank = str(rank)
+        elif isinstance(rank, str):
+            pass
+        else:
+            raise ValueError(f"rank must be a string or an integer but got {type(rank)}")
+
     with global_context_lock:
         global context_dict
         global default_context