def __init__(self,
                 num_classes=80,
                 matcher='HungarianMatcher',
                 loss_coeff={
                     'class': 1,
                     'bbox': 5,
                     'giou': 2,
                     'no_object': 0.1,
                     'mask': 1,
                     'dice': 1
                 },
                 aux_loss=True,
                 use_focal_loss=False,
                 use_vfl=False,
                 vfl_iou_type='bbox',
                 use_uni_match=False,
                 uni_match_ind=0):
        r"""
        Args:
            num_classes (int): The number of classes.
            matcher (HungarianMatcher): It computes an assignment between the targets
                and the predictions of the network.
            loss_coeff (dict): The coefficient of loss.
            aux_loss (bool): If 'aux_loss = True', loss at each decoder layer are to be used.
            use_focal_loss (bool): Use focal loss or not.
        """
        super(DETRLoss, self).__init__()

        self.num_classes = num_classes
        self.matcher = matcher
        self.loss_coeff = loss_coeff
        self.aux_loss = aux_loss
        self.use_focal_loss = use_focal_loss
        self.use_vfl = use_vfl
        self.vfl_iou_type = vfl_iou_type
        self.use_uni_match = use_uni_match
        self.uni_match_ind = uni_match_ind

        if not self.use_focal_loss:
            self.loss_coeff['class'] = paddle.full([num_classes + 1],
                                                   loss_coeff['class'])
            self.loss_coeff['class'][-1] = loss_coeff['no_object']
        self.giou_loss = GIoULoss()

        Args:
            num_classes (int): The number of classes.
            matcher (HungarianMatcher): It computes an assignment between the targets
                and the predictions of the network.
            loss_coeff (dict): The coefficient of loss.
            aux_loss (bool): If 'aux_loss = True', loss at each decoder layer are to be used.
            use_focal_loss (bool): Use focal loss or not.
        
ppdet/modeling/losses/detr_loss.py