src/transformers/trainer_callback.py/EarlyStoppingCallback/__init__
class EarlyStoppingCallback:    def __init__(self, early_stopping_patience: int = 1, early_stopping_threshold: Optional[float] = 0.0):
        self.early_stopping_patience = early_stopping_patience
        self.early_stopping_threshold = early_stopping_threshold
        # early_stopping_patience_counter denotes the number of times validation metrics failed to improve.
        self.early_stopping_patience_counter = 0