def __init__(self, is_training, num_classes):
    """Constructor.

    Args:
      is_training: Indicates whether the BoxPredictor is in training mode.
      num_classes: number of classes.  Note that num_classes *does not*
        include the background category, so if groundtruth labels take values
        in {0, 1, .., K-1}, num_classes=K (and not K+1, even though the
        assigned classification targets can range from {0,... K}).
    """
    self._is_training = is_training
    self._num_classes = num_classes
Constructor.

    Args:
      is_training: Indicates whether the BoxPredictor is in training mode.
      num_classes: number of classes.  Note that num_classes *does not*
        include the background category, so if groundtruth labels take values
        in {0, 1, .., K-1}, num_classes=K (and not K+1, even though the
        assigned classification targets can range from {0,... K}).
    
inference_api/src/main/object_detection/core/box_predictor.py