code: def set_cam(self, cam):
      self.current_cam = cam
  
file_path: PaddleDetection/deploy/pptracking/python/mot/mtmct/zone.py
imports: import os
  import cv2
  import numpy
label_desc: Use image node_id 2 for calling the Zone obj's underlying member method code with example usage: obj.set_cam(cam) without return types