```python
Switch to a different access token.

Args:
token_name (`str`):
Name of the access token to switch to.
add_to_git_credential (`bool`, defaults to `False`):
If `True`, token will be set as git credential. If no git credential helper
is configured, a warning will be displayed to the user. If `token` is `None`,
the value of `add_to_git_credential` is ignored and will be prompted again
to the end user.