code: def center2corner(center):
      """convert (cx, cy, w, h) to (x1, y1, x2, y2)
  
      Parameters
      ----------
          center: list or np.ndarray
              center location, weight and height
  
      Return:
          Corner lefttop and rightdown location
      """
      if isinstance(center, Center):
          center_x, center_y, bbox_w, bbox_h = center
          return Corner(
              center_x - bbox_w * 0.5,
              center_y - bbox_h * 0.5,
              center_x + bbox_w * 0.5,
              center_y + bbox_h * 0.5,
          )
      else:
          center_x, center_y, bbox_w, bbox_h = (
              center[0],
              center[1],
              center[2],
              center[3],
          )
          x_min = center_x - bbox_w * 0.5
          y_min = center_y - bbox_h * 0.5
          x_max = center_x + bbox_w * 0.5
          y_max = center_y + bbox_h * 0.5
          return x_min, y_min, x_max, y_max
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  import math
  from collections import namedtuple
  import numpy
  import mxnet
  from mxnet import nd
  from gluoncv.utils.filesystem import try_import_cv2
label_desc: Use image node_id 3 for calling a global function with example usage: center2corner(center) and returns: Corner, x_min,  y_min,  x_max,  y_max