```python
Enable progress bars either globally or for a specified group.

This function sets the progress bars to enabled for the specified group or globally
if no group is specified. The operation is subject to the `HF_HUB_DISABLE_PROGRESS_BARS`
environment setting.

Args:
name (`str`, *optional*):
The name of the group for which to enable the progress bars. If None,
progress bars are enabled globally.

Raises:
Warning: If the environment variable precludes changes.
```