class_docstr: Randomly crop images and make sure to contain at least one intact
  instance.
code: def __call__(self, results):
      image = results["image"]
      polygons = results["polys"]
      ignore_tags = results["ignore_tags"]
      if len(polygons) < 1:
          return results
  
      if np.random.random_sample() < self.crop_ratio:
          crop_box = self.sample_crop_box(image.shape, results)
          img = self.crop_img(image, crop_box)
          results["image"] = img
          # crop and filter masks
          x1, y1, x2, y2 = crop_box
          w = max(x2 - x1, 1)
          h = max(y2 - y1, 1)
          polygons[:, :, 0::2] = polygons[:, :, 0::2] - x1
          polygons[:, :, 1::2] = polygons[:, :, 1::2] - y1
  
          valid_masks_list = []
          valid_tags_list = []
          for ind, polygon in enumerate(polygons):
              if (
                  (polygon[:, ::2] > -4).all()
                  and (polygon[:, ::2] < w + 4).all()
                  and (polygon[:, 1::2] > -4).all()
                  and (polygon[:, 1::2] < h + 4).all()
              ):
                  polygon[:, ::2] = np.clip(polygon[:, ::2], 0, w)
                  polygon[:, 1::2] = np.clip(polygon[:, 1::2], 0, h)
                  valid_masks_list.append(polygon)
                  valid_tags_list.append(ignore_tags[ind])
  
          results["polys"] = np.array(valid_masks_list)
          results["ignore_tags"] = valid_tags_list
  
      return results
  
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 5 for calling the RandomCropPolyInstances obj's underlying member method code with example usage: obj.__call__(results) and returns: results, results