Function caller_auth_dir 

pub(crate) fn caller_auth_dir(
    provider_id: &str,
    auth_env: &HashMap<String, String>,
) -> Option<String>

The account directory a caller already chose, as auth_env names it under the provider’s auth_config_dir_env_var: the key that keeps a login the caller persists itself (not direct_account) to one live session per directory. None for a provider without one, or when it isn’t set.