src/transformers/integrations.py/WandbCallback/__init__
class WandbCallback:    def __init__(self):
        has_wandb = is_wandb_available()
        assert has_wandb, "WandbCallback requires wandb to be installed. Run `pip install wandb`."
        if has_wandb:
            import wandb

            self._wandb = wandb
        self._initialized = False
        # log outputs
        self._log_model = os.getenv("WANDB_LOG_MODEL", "FALSE").upper() in ENV_VARS_TRUE_VALUES.union({"TRUE"})