Update the auc curve with the given predictions and labels.
Args:
preds (numpy.array): an numpy array in the shape of (batch_size, 2), preds[i][j] denotes the probability of classifying the instance i into the class j.
labels (numpy.array): an numpy array in the shape of (batch_size, 1), labels[i] is either o or 1, representing the label of the instance i.
"""
ifnot_is_numpy_(labels):
raiseValueError("The 'labels' must be a numpy ndarray.")
ifnot_is_numpy_(preds):
raiseValueError("The 'predictions' must be a numpy ndarray.")