class_docstr: Implements a face detector to detect profile pictures on resumes, IDS, driving licenses, passports...
  Based on open CV CascadeClassifier (haarcascades)
  
  Args:
  ----
      n_faces: maximal number of faces to detect on a single image, default = 1
code: def extra_repr(self) -> str:
      return f"n_faces={self.n_faces}"
  
file_path: doctr/doctr/models/artefacts/face.py
imports: from typing import List, Tuple
  import cv2
  import numpy
  from doctr.utils.repr import NestedObject
label_desc: Use image node_id 2 for calling the FaceDetector obj's underlying member method code with example usage: obj.extra_repr() and returns: str, self