class_docstr: FCOSLossMILC for ARSL in semi-det(ssod)
  Args:
      loss_alpha (float): alpha in focal loss
      loss_gamma (float): gamma in focal loss
      iou_loss_type (str): location loss type, IoU/GIoU/LINEAR_IoU
      reg_weights (float): weight for location loss
code: def _bbox_overlap_align(self, pred, targets):
      assert (
          pred.shape[0] == targets.shape[0]
      ), "the pred should be aligned with target."
  
      plw = pred[:, 0]
      pth = pred[:, 1]
      prw = pred[:, 2]
      pbh = pred[:, 3]
  
      tlw = targets[:, 0]
      tth = targets[:, 1]
      trw = targets[:, 2]
      tbh = targets[:, 3]
  
      ilw = paddle.minimum(plw, tlw)
      irw = paddle.minimum(prw, trw)
      ith = paddle.minimum(pth, tth)
      ibh = paddle.minimum(pbh, tbh)
  
      area_predict = (plw + prw) * (pth + pbh)
      area_target = (tlw + trw) * (tth + tbh)
      area_inter = (ilw + irw) * (ith + ibh)
      ious = (area_inter + 1.0) / (
          area_predict + area_target - area_inter + 1.0
      )
  
      return ious
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import paddle
  import paddle.nn
  import paddle.nn.functional
  from ppdet.core.workspace import register
  from ppdet.modeling import ops
  from functools import partial
label_desc: Use image node_id 3 for calling the FCOSLossMILC obj's underlying member method code with example usage: obj._bbox_overlap_align(pred, targets) and returns: ious