code: def apply_coords(self, coords):
      coords = np.concatenate(
          (coords, np.ones((coords.shape[0], 1), dtype="f4")), axis=1
      )
      coords = np.dot(coords, self.mat.T)
      return coords
  
imports: import numpy
  import cv2
  from ...utils.argtools import log_once
  from .base import ImageAugmentor, _default_repr
label_desc: Use image node_id 3 for calling the WarpAffineTransform obj's underlying member method code with example usage: obj.apply_coords(coords) and returns: coords