code: def box_cxcywh_to_xyxy(x):
      x_c, y_c, w, h = x.unbind(-1)
      b = [
          (x_c - 0.5 * w),
          (y_c - 0.5 * h),
          (x_c + 0.5 * w),
          (y_c + 0.5 * h),
      ]
      return paddle.stack(b, axis=-1)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import math
  import copy
  import paddle
  import paddle.nn
  from ppdet.core.workspace import register
  from ppdet.modeling.heads.roi_extractor import RoIAlign
  from ppdet.modeling.bbox_utils import delta2bbox
  from ..None import initializer
label_desc: Use image node_id 1 for calling a global function with example usage: box_cxcywh_to_xyxy(x) and returns: paddle