class_docstr: CTFocalLoss: CornerNet & CenterNet Focal Loss
  Args:
      loss_weight (float): loss weight
      gamma (float): gamma parameter for Focal Loss
code: def __init__(self, loss_weight=1.0, gamma=2.0):
      self.loss_weight = loss_weight
      self.gamma = gamma
  
file_path: PaddleDetection/ppdet/modeling/losses/ctfocal_loss.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import paddle
  from ppdet.core.workspace import register, serializable
label_desc: Use image node_id 1 to create a new CTFocalLoss object from inherited base classes: object with example: obj = CTFocalLoss(loss_weight, gamma)