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 __init__(
      self,
      loss_alpha=0.25,
      loss_gamma=2.0,
      iou_loss_type="giou",
      reg_weights=1.0,
  ):
      super(FCOSLossMILC, self).__init__()
      self.loss_alpha = loss_alpha
      self.loss_gamma = loss_gamma
      self.iou_loss_type = iou_loss_type
      self.reg_weights = reg_weights
  
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 1 to create a new FCOSLossMILC object from inherited base classes: FCOSLoss with example: obj = FCOSLossMILC(loss_alpha, loss_gamma, iou_loss_type, reg_weights)