code: def build_box_head(cfg, input_shape):
      """
      Build a box head defined by `cfg.MODEL.ROI_BOX_HEAD.NAME`.
      """
      name = cfg.MODEL.ROI_BOX_HEAD.NAME
      return ROI_BOX_HEAD_REGISTRY.get(name)(cfg, input_shape)
  
file_path: detectron2/detectron2/modeling/roi_heads/box_head.py
imports: import numpy
  from typing import List
  import fvcore.nn.weight_init
  import torch
  from torch import nn
  from detectron2.config import configurable
  from detectron2.layers import Conv2d, ShapeSpec, get_norm
  from detectron2.utils.registry import Registry
label_desc: Use image node_id 1 for calling a global function with example usage: build_box_head(cfg, input_shape) and returns: ROI_BOX_HEAD_REGISTRY