class_docstr: Assign a corresponding gt bbox or background to each bbox.
  
  Each proposals will be assigned with `0` or a positive integer
  indicating the ground truth index.
  
  - 0: negative sample, no assigned gt
  - positive integer: positive sample, index (1-based) of assigned gt
  
  Args:
      topk (float): number of bbox selected in each level
code: def __init__(
      self,
      topk,
      mode=0,
      iou_calculator=dict(type="BboxOverlaps2D"),
      ignore_iof_thr=-1,
  ):
      self.topk = topk
      self.mode = mode
      self.iou_calculator = build_iou_calculator(iou_calculator)
      self.ignore_iof_thr = ignore_iof_thr
  
file_path: insightface/detection/scrfd/mmdet/core/bbox/assigners/atss_assigner.py
imports: import torch
  from ..builder import BBOX_ASSIGNERS
  from ..iou_calculators import build_iou_calculator
  from .assign_result import AssignResult
  from .base_assigner import BaseAssigner
label_desc: Use image node_id 1 to create a new ATSSAssigner object from inherited base classes: BaseAssigner with example: obj = ATSSAssigner(topk, mode, iou_calculator, ignore_iof_thr)