code: def sample_angle(self, max_angle):
      angle = np.random.random_sample() * 2 * max_angle - max_angle
      return angle
  
imports: import numpy
  from PIL import Image, ImageDraw
  import cv2
  from shapely.geometry import Polygon
  import math
  from ppocr.utils.poly_nms import poly_intersection
label_desc: Use image node_id 4 for calling the RandomRotatePolyInstances obj's underlying member method code with example usage: obj.sample_angle(max_angle) and returns: angle